sbt/main
Ethan Atkins 9d8296fe49 Fix indefinite recompilation
@olegych reported in #4721 that play projects would get stuck in a
strange loop where modifying any source file would cause that source
file to always be recompiled every time a build was triggered regardless
of whether or not it was modified. This was because the play project
sets custom watchSources (using the legacy api) that overlap with the
fileInputs.

There were two parts to this fix:
1) When detecting an event, find if any of the dynamic inputs that cover
   the glob use a hash. If so, these are file inputs so we want to
   update the hash for the path, not the last modified time.
2) Only write hashes into the persistent file stamp cache. Computing the
   last modified time is much cheaper than the hash so it makes sense to
   avoid ever caching last modified times.

I wrote a scripted test that fails if Continuous writes a last modified
time into the file stamp cache instead of a hash. I also verified
manually that a sample play project no longer exhibits the weird
recompilation behavior.

Fixes #4721
2019-05-30 13:02:11 -07:00
..
src Fix indefinite recompilation 2019-05-30 13:02:11 -07:00
NOTICE Add, configure & enforce file headers 2017-10-05 09:03:40 +01:00