InvalidAbsDir "./stack-setupXXXXX" from Path.IO.listDirectory

[robstewart57]

When I execute stack setup I'm getting this error:

$ stack setup
InvalidAbsDir "./stack-setup31658"

This is thrown by Path.parseAbsDir in the path package (see line 79). I've modified Path.IO.listDirectory to print the filepath it is calling parseAbsDir on, so that the file path is printed each time and also so that I can get the stack trace up to that point.

This is the printed file paths and the stack trace:

"/home/rob/.stack/programs/i386-linux/ghc-7.10.2.tar.xz"
"/home/rob/.stack/programs/i386-linux/.."
*** Exception (reporting due to +RTS -xc): (THUNK_1_0), stack trace:
  Path.CAF
  --> evaluated by: Path.IO.listDirectory.\,
  called from Path.IO.listDirectory,
  called from Stack.Setup.listInstalled,
  called from Stack.Setup.ensureGHC,
  called from Stack.Types.StackT.>>=,
  called from Main.setupCmd.\,
  called from Main.withUserFileLock.\,
  called from Main.withUserFileLock,
  called from Main.setupCmd,
  called from Main.main.\,
  called from Data.Attoparsec.Args.withInterpreterArgs,
  called from Main.main

I've raised this question with @chrisdone who believes that stack should canonicalize paths before calling parseAbsDir.

[mgsloan]

configLocalPrograms seems to be well canonicalized, here, so it must not be the input to listDirectory that's the issue.

It's very surprising that there'd be a bug in listDirectory, though (you'd think it'd always happen, and be caught quickly).

Lets test out chris's thought - does this fix it?

diff --git a/src/Path/IO.hs b/src/Path/IO.hs
index ca1bed9..79e6d39 100644
--- a/src/Path/IO.hs
+++ b/src/Path/IO.hs
@@ -170,8 +170,9 @@ listDirectory dir =
   do entriesFP <- liftIO (D.getDirectoryContents dirFP)
      maybeEntries <-
        forM (map (dirFP ++) entriesFP)
-            (\entryFP ->
-               do isDir <- liftIO (D.doesDirectoryExist entryFP)
+            (\entryFP' ->
+               do entryFP <- liftIO (D.canonicalizePath entryFP')
+                  isDir <- liftIO (D.doesDirectoryExist entryFP)
                   if isDir
                      then case parseAbsDir entryFP of
                             Nothing -> return Nothing

[chrisdone]

The calls to parseAbsDir inside listDirectory are in the Maybe monad so I don't see why an exception would be thrown from within listDirectory.

[chrisdone]

@robstewart57 Can you offer some extra details so that we can reproduce this?

[robstewart57]

In fact, I wasn't reading the stack trace in the right way. It turns out that the issue was with Stack.Setup whenever withSystemTempDirectory is used, e.g.

withSystemTempDirectory "stack-setup" $ \root' -> do
root <- parseAbsDir root'

At least for me, the withSystemTempDirectory was not returning a canonicalised path, which is why parseAbsDir from the path library was throwing the error.

I propose a PR that applies a fix to stack setup, sanityCheck and stack upgrade
in Stack.Setup : #1019 .

[robstewart57]

Hang off accepting this PR actually, this same problem is causing a problem elsewhere. More anon...

[robstewart57]

OK, that second commit ( f912e2f ) does appear to fix the InvalidAbsDir error I was getting. This PR is ready for review #1019 .

[snoyberg]

Closing so that we follow up on the PR (#1019).