Jonathan Nieder <jrnieder@xxxxxxxxx> writes: > Variables from the inherited environment that are meaningful to git > can break tests in undesirable ways. For example, > > GIT_PAGER=more sh t5400-send-pack.sh -v -i > > hangs. So unset all environment variables in the GIT_ namespace in > test-lib, with a few exceptions: > > - GIT_TRACE* are useful for tracking down bugs exhibited by a failing > test; > > - GIT_DEBUG* are GIT_TRACE variables by another name, practically > speaking. They should probably be tweaked to follow the > GIT_TRACE_foo scheme and use trace_printf machinery some time. > > - GIT_USE_LOOKUP from v1.5.6-rc0~134^2~1 (sha1-lookup: more memory > efficient search in sorted list of SHA-1, 2007-12-29) is about > trying an alternate implementation strategy rather than changing > semantics and it can be useful to compare performance with and > without it set. > > Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx> > --- > Thanks again. Sounds sane. I am perfectly fine with the use of perl but do we know the "perl" binary found on $PATH (as opposed to $PERL_PATH) is good to use for this purpose? The features used in the scriptlet seem so bread-and-butter that I don't think it would make too much of a difference, but we may want to be consistent. I personally think USE_LOOKUP outlived its usefulness. It was meant to be an easy way to experiment if the sha1_entry_pos() lookup gives better performance while looking up a pack entry, to choose one implementation and discard the other, but I don't think anybody actually did meaningful benchmarks to decide which one to keep. Perhaps we should discard the codepath USE_LOOKUP turns on, which I suspect hasn't been exercised since v1.5.6 days by anybody. An obvious alternative is for somebody to try using USE_LOOKUP and see if it really gives a better performance with large packs (and if so, always use it and discard the other codepath). Obviously that is outside the scope of this patch series, but I thought I should mention it before I forget. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html