Stack: `stack solver` gets caught on infinite symlink loops

[khouli]

General summary/comments

On macOS, stack solver appears to choke on symlinks under ~/Library/Application Support that point to parent directories. I encountered this with a symlink created by Steam that looks like this:

~/Library/Application Support/Steam/Steam.AppBundle/Steam/Contents/MacOS/Frameworks/Steam Helper EH.app/Contents/Frameworks -> ../../../Frameworks

I couldn't reproduce this by adding my own circular symlink in ~/Library/Application Support.

Steps to reproduce

On macOS:

1. Install Steam (or presumably create a similar directory structure although I couldn't reproduce it this way).
2. Run stack solver.

Expected

stack only follows a particular symlink once.

Actual

stack may follow the same symlink endlessly.

$ stack solver -v
Version 1.6.3 x86_64 hpack-0.20.0
2018-01-31 15:16:36.602569: [debug] Checking for project config at: /Users/khouli/stack.yaml
@(Stack/Config.hs:842:9)
2018-01-31 15:16:36.603219: [debug] Checking for project config at: /Users/stack.yaml
@(Stack/Config.hs:842:9)
2018-01-31 15:16:36.603344: [debug] Checking for project config at: /stack.yaml
@(Stack/Config.hs:842:9)
2018-01-31 15:16:36.603413: [debug] No project config file found, using defaults.
@(Stack/Config.hs:872:13)
2018-01-31 15:16:36.605563: [debug] Run from outside a project, using implicit global project config
@(Stack/Config.hs:559:13)
2018-01-31 15:16:36.606076: [debug] Using resolver: lts-10.4 from implicit global project's config file: /Users/khouli/.stack/global-project/stack.yaml
@(Stack/Config.hs:573:32)
2018-01-31 15:16:36.606191: [debug] Decoding build plan from: /Users/khouli/.stack/build-plan/lts-10.4.yaml
@(Stack/Snapshot.hs:150:5)
2018-01-31 15:16:36.606271: [debug] Trying to decode /Users/khouli/.stack/build-plan-cache/lts-10.4.cache
@(Data/Store/VersionTagged.hs:66:5)
2018-01-31 15:16:36.634583: [debug] Success decoding /Users/khouli/.stack/build-plan-cache/lts-10.4.cache
@(Data/Store/VersionTagged.hs:70:13)
2018-01-31 15:16:36.635231: [debug] Using standard GHC build
@(Stack/Setup.hs:617:9)
2018-01-31 15:16:36.637726: [debug] Getting global package database location
@(Stack/GhcPkg.hs:46:5)
2018-01-31 15:16:36.638855: [debug] Asking GHC for its version
@(Stack/Setup/Installed.hs:98:13)
2018-01-31 15:16:36.640022: [debug] Run process: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc-pkg --no-user-package-db list --global
@(System/Process/Log.hs:37:3)
2018-01-31 15:16:36.640165: [debug] Getting Cabal package version
@(Stack/GhcPkg.hs:185:5)
2018-01-31 15:16:36.663772: [debug] Run process: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc --numeric-version
@(System/Process/Log.hs:37:3)
2018-01-31 15:16:36.664086: [debug] Run process: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc-pkg --no-user-package-db field --simple-output Cabal version
@(System/Process/Log.hs:37:3)
2018-01-31 15:16:36.791997: [debug] Process finished in 151ms: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc-pkg --no-user-package-db list --global
@(System/Process/Log.hs:44:3)
2018-01-31 15:16:36.807012: [debug] Process finished in 142ms: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc-pkg --no-user-package-db field --simple-output Cabal version
@(System/Process/Log.hs:44:3)
2018-01-31 15:16:36.837523: [debug] Process finished in 173ms: /Users/khouli/.stack/programs/x86_64-osx/ghc-8.2.2/bin/ghc --numeric-version
@(System/Process/Log.hs:44:3)
2018-01-31 15:16:36.838046: [debug] GHC version is: ghc-8.2.2
@(Stack/Setup/Installed.hs:102:13)
2018-01-31 15:16:36.838239: [debug] Resolving package entries
@(Stack/Setup.hs:250:5)
2018-01-31 15:16:36.838748: [debug] Trying to decode /Users/khouli/.stack/loaded-snapshot-cache/x86_64-osx/ghc-8.2.2/lts-10.4.cache
@(Data/Store/VersionTagged.hs:66:5)
2018-01-31 15:16:36.900745: [debug] Success decoding /Users/khouli/.stack/loaded-snapshot-cache/x86_64-osx/ghc-8.2.2/lts-10.4.cache
@(Data/Store/VersionTagged.hs:70:13)
2018-01-31 15:16:36.901547: [debug] Starting to execute command inside EnvConfig
@(Stack/Runners.hs:170:18)
2018-01-31 15:16:36.901723: [info] Using configuration file: .stack/global-project/stack.yaml
@(Stack/Solver.hs:635:5)
2018-01-31 15:16:36.901818: [debug] Trying to decode /Users/khouli/.stack/indices/Hackage/01-index.cache
@(Data/Store/VersionTagged.hs:66:5)
2018-01-31 15:16:37.114223: [debug] Success decoding /Users/khouli/.stack/indices/Hackage/01-index.cache
@(Data/Store/VersionTagged.hs:70:13)
/Users/khouli/Library/Application Support/Steam/Steam.AppBundle/Steam/Contents/MacOS/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Steam Helper EH.app/Contents/Frameworks/Chromium Embedded Framework.framework/Resources/: getSymbolicLinkStatus: invalid argument (File name too long)

Stack version

$ stack --version
Version 1.6.3 x86_64 hpack-0.20.0

Method of installation

• homebrew, default options

[matthewess]

Is there a workaround for this? I feel like it's sane to want to run stack solver on the global project (although perhaps I'm wrong?)

[RosalesJ]

Hoping this issue gets addressed, I can't run stack solver for this reason even after renaming the symlink.

[harendra-kumar]

The problem may be because stack is using its own directory traversal routines which follow symlinks and does not avoid loops. I changed the default behavior in the path-io package some time back to not follow symlinks by default e.g. see listDirRecur in this https://hackage.haskell.org/package/path-io-1.3.3/docs/Path-IO.html. I also added a walkDir routine in path-io which can detect and avoid loops. I guess these APIs can be used to solve this issue.

[mihaimaruseac]

Can you attempt a PR with the fixes, @harendra-kumar? Thanks

[harendra-kumar]

@mihaimaruseac I am pretty busy with work these days, you cannot rely on me. Maybe someone else should take it up, I can help in reviewing though.

[snoyberg]

We've removed the solver support in #4670