test-merge-changedelete.t fails with my hgmerge

[timeless]

$ cat ~/bin/hgmerge
#!/bin/sh
hg merge $1 && hg commit -m "merging: $1"

I have that because it was a convenient thing for doing a sort of
merge I did a lot at some point.

Two points:
1. The tests afaik are supposed to be self-contained.
2. The error reporting here was incredibly unhelpful. I shouldn't have
to insert dozens of debug statements to find out that `hg merge`
called an `hgmerge` script and that the script failed. hg should tell
me that it called `hgmerge` and that it failed.

[timeless at gcc2-power8 tests]$ ./run-tests.py test-merge-changedelete.t

--- /home/timeless/hg/crewplan/tests/test-merge-changedelete.t
+++ /home/timeless/hg/crewplan/tests/test-merge-changedelete.t.err
@@ -59,7 +59,8 @@
   other [merge rev] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? u
   merging file3
-  warning: conflicts while merging file3! (edit, then use 'hg resolve --mark')
+  hg: parse error at 0: syntax error in revset '$TESTTMP/repo/file3'
+  merging file3 failed!
   0 files updated, 0 files merged, 0 files removed, 3 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to aband
on
   [1]
@@ -103,11 +104,7 @@
   changed
   --- file3 ---
   3
-  <<<<<<< working copy: 13910f48cf7b - test: changed file1, removed file2, chan
...
   changed2
-  =======
-  changed1
-  >>>>>>> merge rev:    10f9a0a634e8 - test: removed file1, changed file2, chan
...


 Interactive merge:
...