Fixes haskell#3323 and haskell#3324, ensuring we monitor the project Cabal files. Original fix by Edward Z. Yang. The approach in this patch is to fix an underlying problem. Subsequent patches use a more consistent approach to the monitoring as suggested by Edward. The motivating example is: matches <- matchFileGlob dirname glob where matchFileGlob is defined in the RebuildMonad module as matchFileGlob root glob = do monitorFiles [monitorFileGlob glob] liftIO $ Glob.matchFileGlob root glob This usage is wrong because the root used to match the glob is not the same as the root that will be used later when checking the file monitor for changes. You can see this is suspicious because the declaration of the monitor does not take an root dir paramater but the immediate matching does. That's because the root for the monitors is specified when we do the rerunIfChanged to check the monitor. So the only correct usage involves passing in the correct root. This is a ripe source of bugs. So this refactoring moves the root into the Rebuild monad directly, so the example becomes: matches <- matchFileGlob glob The root is implicit, so you can't accidentally pick a different root for the immediate match vs the later monitor check. Of course the root still matters, but if you get that wrong you'll notice immediately because you will not get the match results you were expecting. So the root is now passed in with runRebuild, not with rerunIfChanged. Also change the incorrect use of matchFileGlob. This use case now relies on the adjusted representation of glob roots, using FilePath.splitDrive to obtain the root (if any).

Commits

Commits on Apr 17, 2016

Adjust representation of file glob roots

Refactor the Rebuild monad to keep file root in Reader env

Clarify relative vs absolute paths in project package locations

matchFileGlob should only monitor for existence

Adjust tests for monitoring Cabal files to cover more cases