test-bisect: normalize shell error message

Different shells on vary in their error messages. Here we're satisfied
if the shell mentions './foobar' at all.

tests/test-bisect

@@ -1,106 +1,106 b''
 #!/bin/sh
 
 set -e
 
 echo % init
 hg init
 
 echo % committing changes
 count=0
 echo > a
 while test $count -lt 32 ; do
     echo 'a' >> a
     test $count -eq 0 && hg add
     hg ci -m "msg $count" -d "$count 0"
     echo % committed changeset $count
     count=`expr $count + 1`
 done
 
 echo % log
 hg log
 
 echo % hg up -C
 hg up -C
 
 echo % bisect test
 hg bisect -r
 hg bisect -b
 hg bisect -g 1
 hg bisect -g
 echo skip
 hg bisect -s
 hg bisect -g
 hg bisect -g
 hg bisect -b
 hg bisect -g
 
 echo % bisect reverse test
 hg bisect -r
 hg bisect -b null
 hg bisect -g tip
 hg bisect -g
 echo skip
 hg bisect -s
 hg bisect -g
 hg bisect -g
 hg bisect -b
 hg bisect -g
 
 hg bisect -r
 hg bisect -g tip
 hg bisect -b tip || echo error
 
 hg bisect -r
 hg bisect -g null
 hg bisect -bU tip
 hg id
 
 echo % reproduce AssertionError, issue1228 and issue1182
 hg bisect -r
 hg bisect -b 4
 hg bisect -g 0
 hg bisect -s
 hg bisect -s
 hg bisect -s
 
 echo % reproduce non converging bisect, issue1182
 hg bisect -r
 hg bisect -g 0
 hg bisect -b 2
 hg bisect -s
 
 echo % test no action
 hg bisect -r
 hg bisect || echo failure
 
 echo % reproduce AssertionError, issue1445
 hg bisect -r
 hg bisect -b 6
 hg bisect -g 0
 hg bisect -s
 hg bisect -s
 hg bisect -s
 hg bisect -s 
 hg bisect -g
 
 set +e
 
 echo % test invalid command
 hg bisect -r
-hg bisect --command './foobar' 2>&1 | sed 's/: command/:/'
+hg bisect --command './foobar' 2>&1 | sed 's|\(/bin/sh: \./foobar:\).*|\1 not found|'
 
 echo % test bisecting command
 cat > script.py <<EOF
 #!/usr/bin/env python
 import sys
 from mercurial import ui, hg
 repo = hg.repository(ui.ui(), '.')
 if repo['.'].rev() < 6:
     sys.exit(1)
 EOF
 chmod +x script.py
 hg bisect -r
 hg bisect --good tip
 hg bisect --bad 0
 hg bisect --command "`pwd`/script.py"
 true