tests: add optional output when wheel is missing
If the `wheel` package isn't installed, pip will emit a warning
on stderr complaining about that. Alternatively, we could
redirect stderr to stdout and swallow the warning. But I like
tests having visibility of warnings, as it helps keep us honest
regarding edge cases.
Differential Revision: https://phab.mercurial-scm.org/D7371
--- a/tests/test-install.t Wed Aug 28 17:43:56 2019 -0700
+++ b/tests/test-install.t Mon Nov 11 19:04:49 2019 -0800
@@ -250,6 +250,7 @@
Note: we use this weird path to run pip and hg to avoid platform differences,
since it's bin on most platforms but Scripts on Windows.
$ ./installenv/*/pip install --no-index $TESTDIR/.. >> pip.log
+ Failed building wheel for mercurial (?)
$ ./installenv/*/hg debuginstall || cat pip.log
checking encoding (ascii)...
checking Python executable (*) (glob)