cache vs don't cache absolute filepaths

[kevinburkeshyp]

I wrote this: Shyp@f21238c

then realized it's not the right thing really... we don't care about absolute vs. relative, so much as we care about whether the path references something on the filesystem, or a module name..

For what it's worth I didn't see any measurable perf difference with this patch, but I wasn't rigorous about testing it.

[kevinburkeshyp]

I wrote the right thing and it changes the test run time from 6-6.5s to 5.3-5.5s. Without the patch, the test run time is ~5.1s.

[bahmutov]

Did not look at this - is it worth incorporating this into the master?

[kevinburkeshyp]

Prolly should do some more testing first... I didn't see much of a difference either way.