rhg: add a limited `rhg root` subcommand

Clap has been choosen for argument parsing for the following reasons:

- it's a wildly used and maintained crate
- it can deal with OS encoding making it suitable for any encoding
- it supports nonambiguous prefix matching as already available in hg
- it will soon allow for structopts-style declarative pattern instead of the
  currently used builder pattern

Differential Revision: https://phab.mercurial-scm.org/D8613

tests/test-rhg.t

@@ -0,0 +1,26 b''
+#require rust
+
+  $ rhg() {
+  > if [ -f "$RUNTESTDIR/../rust/target/debug/rhg" ]; then
+  >   "$RUNTESTDIR/../rust/target/debug/rhg" "$@"
+  > else
+  >   echo "skipped: Cannot find rhg. Try to run cargo build in rust/rhg."
+  >   exit 80
+  > fi
+  > }
+  $ rhg unimplemented-command
+  [252]
+  $ rhg root
+  abort: no repository found in '$TESTTMP' (.hg not found)!
+  [255]
+  $ hg init repository
+  $ cd repository
+  $ rhg root
+  $TESTTMP/repository
+  $ rhg root > /dev/full
+  abort: No space left on device (os error 28)
+  [255]
+  $ rm -rf `pwd`
+  $ rhg root
+  abort: error getting current working directory: $ENOENT$
+  [255]

rust/Cargo.lock

@@ -1,726 +1,727 b''
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
 version = "0.7.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "atty"
 version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "hermit-abi 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "autocfg"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "byteorder"
 version = "1.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "chrono"
 version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "num-integer 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "clap"
-version = "2.33.0"
+version = "2.33.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-width 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "colored"
 version = "1.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "cpython"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "python27-sys 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "python3-sys 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-deque 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-epoch 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-queue 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam-channel"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam-deque"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-epoch 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam-epoch"
 version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "memoffset 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam-queue"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "crossbeam-utils"
 version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "ctor"
 version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "difference"
 version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "either"
 version = "1.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "getrandom"
 version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasi 0.9.0+wasi-snapshot-preview1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "hermit-abi"
 version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "hex"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "hg-core"
 version = "0.1.0"
 dependencies = [
  "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clap 2.33.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "memmap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "micro-timer 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_distr 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_pcg 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "twox-hash 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "hg-cpython"
 version = "0.1.0"
 dependencies = [
  "cpython 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hg-core 0.1.0",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "simple_logger 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "libc"
 version = "0.2.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "log"
 version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "maybe-uninit"
 version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memchr"
 version = "2.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memmap"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "memoffset"
 version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "micro-timer"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "micro-timer-macros 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "micro-timer-macros"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "num-integer"
 version = "0.1.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "num-traits"
 version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "num_cpus"
 version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "hermit-abi 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "output_vt100"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "ppv-lite86"
 version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "pretty_assertions"
 version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ctor 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "output_vt100 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "proc-macro2"
 version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "python27-sys"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "python3-sys"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "quote"
 version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "getrandom 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_chacha"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_core"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "getrandom 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_distr"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_hc"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_pcg"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rayon"
 version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-deque 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon-core 1.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rayon-core"
 version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-deque 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-queue 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "regex"
 version = "1.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "aho-corasick 0.7.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_local 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "regex-syntax"
 version = "0.6.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "remove_dir_all"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rhg"
 version = "0.1.0"
 dependencies = [
+ "clap 2.33.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hg-core 0.1.0",
 ]
 
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "same-file"
 version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "semver"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "semver-parser"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "simple_logger"
 version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "colored 1.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "strsim"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "syn"
 version = "1.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "tempfile"
 version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
  "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "textwrap"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "unicode-width 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "thread_local"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "time"
 version = "0.1.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "twox-hash"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "unicode-width"
 version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "unicode-xid"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "vec_map"
 version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "wasi"
 version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "winapi"
 version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "winapi-i686-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "winapi-util"
 version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
 "checksum aho-corasick 0.7.10 (registry+https://github.com/rust-lang/crates.io-index)" = "8716408b8bc624ed7f65d223ddb9ac2d044c0547b6fa4b0d554f3a9540496ada"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
 "checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 "checksum byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "80094f509cf8b5ae86a4966a39b3ff66cd7e2a3e594accec3743ff3fabeab5b2"
-"checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
+"checksum clap 2.33.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bdfa80d47f954d53a35a64987ca1422f495b8d6483c0fe9f7117b36c2a792129"
 "checksum colored 1.9.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f4ffc801dacf156c5854b9df4f425a626539c3a6ef7893cc0c5084a23f0b6c59"
 "checksum cpython 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bfaf3847ab963e40c4f6dd8d6be279bdf74007ae2413786a0dcbb28c52139a95"
 "checksum crossbeam 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "69323bff1fb41c635347b8ead484a5ca6c3f11914d784170b158d8449ab07f8e"
 "checksum crossbeam-channel 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "cced8691919c02aac3cb0a1bc2e9b73d89e832bf9a06fc579d4e71b68a2da061"
 "checksum crossbeam-deque 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9f02af974daeee82218205558e51ec8768b48cf524bd01d550abe5573a608285"
 "checksum crossbeam-epoch 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "058ed274caafc1f60c4997b5fc07bf7dc7cca454af7c6e81edffe5f33f70dace"
 "checksum crossbeam-queue 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c695eeca1e7173472a32221542ae469b3e9aac3a4fc81f7696bcad82029493db"
 "checksum crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 "checksum ctor 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "47c5e5ac752e18207b12e16b10631ae5f7f68f8805f335f9b817ead83d9ffce1"
 "checksum difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 "checksum either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
 "checksum getrandom 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
 "checksum hermit-abi 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "1010591b26bbfe835e9faeabeb11866061cc7dcebffd56ad7d0942d0e61aefd8"
 "checksum hex 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "644f9158b2f133fd50f5fb3242878846d9eb792e445c893805ff0e3824006e35"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 "checksum libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)" = "eb147597cdf94ed43ab7a9038716637d2d1bf2bc571da995d0028dec06bd3018"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "60302e4db3a61da70c0cb7991976248362f30319e88850c487b9b95bbf059e00"
 "checksum memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
 "checksum memmap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
 "checksum memoffset 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "75189eb85871ea5c2e2c15abbdd541185f63b408415e5051f5cac122d8c774b9"
 "checksum micro-timer 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "25b31d6cb9112984323d05d7a353f272ae5d7a307074f9ab9b25c00121b8c947"
 "checksum micro-timer-macros 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5694085dd384bb9e824207facc040c248d9df653f55e28c3ad0686958b448504"
 "checksum num-integer 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "3f6ea62e9d81a77cd3ee9a2a5b9b609447857f3d358704331e4ef39eb247fcba"
 "checksum num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "c62be47e61d1842b9170f0fdeec8eba98e60e90e5446449a0545e5152acd7096"
 "checksum num_cpus 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "46203554f085ff89c235cd12f7075f3233af9b11ed7c9e16dfe2560d03313ce6"
 "checksum output_vt100 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "53cdc5b785b7a58c5aad8216b3dfa114df64b0b06ae6e1501cef91df2fbdf8f9"
 "checksum ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
 "checksum pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3f81e1644e1b54f5a68959a29aa86cde704219254669da328ecfdf6a1f09d427"
 "checksum proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6c09721c6781493a2a492a96b5a5bf19b65917fe6728884e7c44dd0c60ca3435"
 "checksum python27-sys 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "67cb041de8615111bf224dd75667af5f25c6e032118251426fed7f1b70ce4c8c"
 "checksum python3-sys 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90af11779515a1e530af60782d273b59ac79d33b0e253c071a728563957c76d4"
 "checksum quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2bdc6c187c65bca4260c9011c9e3132efe4909da44726bad24cf7572ae338d7f"
 "checksum rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
 "checksum rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
 "checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
 "checksum rand_distr 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "96977acbdd3a6576fb1d27391900035bf3863d4a16422973a409b488cf29ffb2"
 "checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
 "checksum rand_pcg 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "16abd0c1b639e9eb4d7c50c0b8100b0d0f849be2349829c740fe8e6eb4816429"
 "checksum rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "db6ce3297f9c85e16621bb8cca38a06779ffc31bb8184e1be4bed2be4678a098"
 "checksum rayon-core 1.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "08a89b46efaf957e52b18062fb2f4660f8b8a4dde1807ca002690868ef2c85a9"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9c3780fcf44b193bc4d09f36d2a3c87b251da4a046c87795a0d35f4f927ad8e6"
 "checksum regex-syntax 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)" = "26412eb97c6b088a6997e05f69403a802a92d520de2f8e63c2b65f9e0f47c4e8"
 "checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 "checksum scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum simple_logger 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fea0c4611f32f4c2bac73754f22dca1f57e6c1945e0590dae4e5f2a077b92367"
 "checksum strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 "checksum syn 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)" = "123bd9499cfb380418d509322d7a6d52e5315f064fe4b3ad18a53d6b92c07859"
 "checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 "checksum textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
 "checksum thread_local 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
 "checksum twox-hash 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3bfd5b7557925ce778ff9b9ef90e3ade34c524b5ff10e239c69a42d546d2af56"
 "checksum unicode-width 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "caaa9d531767d1ff2150b9332433f32a24622147e5ebb1f26409d5da67afd479"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 "checksum wasi 0.9.0+wasi-snapshot-preview1 (registry+https://github.com/rust-lang/crates.io-index)" = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4ccfbf554c6ad11084fb7517daca16cfdcaccbdadba4fc336f032a8b12c2ad80"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

rust/rhg/Cargo.toml

@@ -1,9 +1,10 b''
 [package]
 name = "rhg"
 version = "0.1.0"
 authors = ["Antoine Cezar <[e-mail]>"]
 edition = "2018"
 
 [dependencies]
 hg-core = { path = "../hg-core"}
+clap = "2.33.1"
 

rust/rhg/src/main.rs

@@ -1,8 +1,42 b''
+use clap::App;
+use clap::AppSettings;
+use clap::SubCommand;
+
 mod commands;
 mod error;
 mod exitcode;
 mod ui;
+use commands::Command;
 
 fn main() {
-    std::process::exit(exitcode::UNIMPLEMENTED_COMMAND)
+    let mut app = App::new("rhg")
+        .setting(AppSettings::AllowInvalidUtf8)
+        .setting(AppSettings::SubcommandRequired)
+        .setting(AppSettings::VersionlessSubcommands)
+        .version("0.0.1")
+        .subcommand(
+            SubCommand::with_name("root").about(commands::root::HELP_TEXT),
+        );
+
+    let matches = app.clone().get_matches_safe().unwrap_or_else(|_| {
+        std::process::exit(exitcode::UNIMPLEMENTED_COMMAND)
+    });
+
+    let command_result = match matches.subcommand_name() {
+        Some(name) => match name {
+            "root" => commands::root::RootCommand::new().run(),
+            _ => std::process::exit(exitcode::UNIMPLEMENTED_COMMAND),
+        },
+        _ => {
+            match app.print_help() {
+                Ok(_) => std::process::exit(exitcode::OK),
+                Err(_) => std::process::exit(exitcode::ABORT),
+            };
+        }
+    };
+
+    match command_result {
+        Ok(_) => std::process::exit(exitcode::OK),
+        Err(e) => e.exit(),
+    }
 }