Ticket #3090 (closed bug: wontfix)
ghc-pkg update should fail if dependent packages might break
|Reported by:||simonmar||Owned by:|
|Type of failure:||None/Unknown||Difficulty:||Unknown|
|Test Case:||Blocked By:|
If a package is recompiled and re-installed, and other packages depend on it, those packages might be broken; e.g. see #3060.
Hence ghc-pkg update should refuse to perform the update, unless explicitly overridden with --force. However, it's not quite as simple as that:
- The package might already have been installed over the top of the old one, and it's too late to reverse that.
- cabal-install likes to build and install a bunch of packages at the same time, using ghc-pkg update on each one. This will fail.
- The GHC build system uses ghc-pkg update to register packages, and this breaks when packages are re-built (it's ok for a clean build, though).
I've attached a couple of patches to implement it, but let's hold these back until the above issues are sorted out.