Race hazard in Random library test suite

[simonpj]

In a validate run, rangeTest fails thus

=====> rangeTest(normal) 2838 of 2886 [0, 4, 0]
cd ../../../libraries/random/tests && '/64playpen/simonpj/builds/HEAD-1/bindisttest/install dir/bin/ghc' -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-conf -rtsopts  -o rangeTest rangeTest.hs  -i.. -XCPP   >rangeTest.comp.stderr 2>&1
=====> random1283(normal) 2839 of 2886 [0, 4, 0]
cd ../../../libraries/random/tests && '/64playpen/simonpj/builds/HEAD-1/bindisttest/install dir/bin/ghc' -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-conf -rtsopts  -o random1283 random1283.hs  -i.. -XCPP  -package containers  >random1283.comp.stderr 2>&1
Compile failed (status 256) errors were:
[1 of 2] Compiling System.Random    ( ../System/Random.hs, ../System/Random.o )
[2 of 2] Compiling Main             ( rangeTest.hs, rangeTest.o )
Linking rangeTest ...
../System/Random.o: file not recognized: File truncated
collect2: ld returned 1 exit status

*** unexpected failure for rangeTest(normal)

Ian writes: The problem is this, in libraries/random/tests/all.T:

    # This lets me run tests from the test directory during development:
    opts = '-i.. -XCPP '

This is causing all the tests to compile the source, rather than using the package. If two of the tests get run in parallel then there is a race condition.

Ryan, could you handle this differently, so those flags don't get passed by default, please? Perhaps have them conditionally set, based on whether a file has been 'touch'ed or whether a make variable has been set, or maybe make a testsuite wrapper for yourself which builds the package so that they aren't necessary?

[rrnewton]

Ah, it looks like my first attempt to add a new test was bungled.

Does it seem like simply removing the opts line is a sufficient fix? I believe so. Therefore I've checked in that small change.

Alas, I'm running into other problems when I try to validate GHC on my mac/ubuntu machines so for the time being I can't test this properly through the normal harness.

[igloo]

changeset:806f9fb0431d542821e22dac927169307faf8a35 is now in the GHC HEAD repo, thanks!