manzyuk
commented
11 years ago I'm at OdHac at the moment and am trying to do some work on Cabal, so I've looked at this issue for warmup.
The problem is indeed in the function Distribution.Simple.Utils.wrapText, which is used to wrap messages at 79 characters. No attempt is made to detect whether a space at which a line is wrapped is part of a file name. One can reproduce the problem more easily as follows:
$ cabal install http://hackage.haskell.org/packages/archive/groups/0.2.0.1/groups-0.2.0.1.tar.gz --prefix "/home/manzyuk/foo/bar/baz quux" Downloading http://hackage.haskell.org/packages/archive/groups/0.2.0.1/groups-0.2.0.1.tar.gz Resolving dependencies... In order, the following will be installed: groups-0.2.0.1 (reinstall) Warning: Note that reinstalls are always dangerous. Continuing anyway... Configuring groups-0.2.0.1... Building groups-0.2.0.1... Preprocessing library groups-0.2.0.1... [1 of 1] Compiling Data.Group ( src/Data/Group.hs, dist/build/Data/Group.o ) In-place registering groups-0.2.0.1... Installing library in /home/manzyuk/foo/bar/baz quux/lib/groups-0.2.0.1/ghc-7.4.1 Registering groups-0.2.0.1... Installed groups-0.2.0.1
Note that the line starting with "Installing library in" is wrapped at the space that is part of a directory name.
I suppose, a proper way to fix it would be to use an algebraic data type rather than String to represent messages, something like Text.PrettyPrint.Doc, so that file names can be treated as unbreakable entities that shouldn't be wrapped. This, however, seems to require quite some re-engineering of error handling in Cabal. Should I go ahead and do it?
23Skidoo
BardurArantsson
ezyang
(Imported from Trac #833, reported by @igloo on 2011-04-21)
Cabal mangles exceptions, e.g.:
where a space in the filename has been replaced with a '\n'. This can be very confusing! It looks like Distribution.Simple.Utils.topHandler / wrapText is the culprit.