convert: document source and sink identifiers, fix error message

hgext/convert/__init__.py

@@ -14,18 +14,18 b' from mercurial import commands'
 def convert(ui, src, dest=None, revmapfile=None, **opts):
     """Convert a foreign SCM repository to a Mercurial one.
 
-    Accepted source formats:
-    - Mercurial
-    - CVS
-    - Darcs
-    - git
-    - Subversion
-    - Monotone
-    - GNU Arch
+    Accepted source formats [identifiers]:
+    - Mercurial [hg]
+    - CVS [cvs]
+    - Darcs [darcs]
+    - git [git]
+    - Subversion [svn]
+    - Monotone [mtn]
+    - GNU Arch [gnuarch]
 
-    Accepted destination formats:
-    - Mercurial
-    - Subversion (history on branches is not preserved)
+    Accepted destination formats [identifiers]:
+    - Mercurial [hg]
+    - Subversion [svn] (history on branches is not preserved)
 
     If no revision is given, all revisions will be converted. Otherwise,
     convert will only import up to the named revision (given in a format

hgext/convert/convcmd.py

@@ -53,7 +53,7 b' def convertsource(ui, path, type, rev):'
     if not ui.quiet:
         for inst in exceptions:
             ui.write("%s\n" % inst)
-    raise util.Abort(_('%s: unknown repository type') % path)
+    raise util.Abort(_('%s: missing or unsupported repository') % path)
 
 def convertsink(ui, path, type):
     for name, sink in sink_converters:

tests/test-convert.out

@@ -2,18 +2,18 b' hg convert [OPTION]... SOURCE [DEST [REV'
 
 Convert a foreign SCM repository to a Mercurial one.
 
-    Accepted source formats:
-    - Mercurial
-    - CVS
-    - Darcs
-    - git
-    - Subversion
-    - Monotone
-    - GNU Arch
+    Accepted source formats [identifiers]:
+    - Mercurial [hg]
+    - CVS [cvs]
+    - Darcs [darcs]
+    - git [git]
+    - Subversion [svn]
+    - Monotone [mtn]
+    - GNU Arch [gnuarch]
 
-    Accepted destination formats:
-    - Mercurial
-    - Subversion (history on branches is not preserved)
+    Accepted destination formats [identifiers]:
+    - Mercurial [hg]
+    - Subversion [svn] (history on branches is not preserved)
 
     If no revision is given, all revisions will be converted. Otherwise,
     convert will only import up to the named revision (given in a format