Re: Build failure -- missing dependency? Help!

On Mar 14, 2021, at 6:53 PM, Simon Peyton Jones via ghc-devs wrote:

I’m getting this (with ‘sh validate –legacy’). Oddly

• It does not happen on HEAD • It does happen on wip/T19495, a tiny patch with one innocuous change to GHC.Tc.Gen.HsType I can’t see how my patch could possible cause “missing files” in ghc-bignum!

I’m guessing that there is a missing dependency that someone doesn’t show up in master, but does in my branch, randomly.

There’s something funny about ghc-bignum; it doesn’t seem to be a regular library

Can anyone help?

I managed to reproduce the issue on my machine, and noticed that after: $ cd libraries/ghc-bignum/ $ gmake $ cd ../.. $ ./validate --legacy --no-clean the build continues OK. So it looks like the legacy parallel build has a missing dependency on the completion of the build of libraries/ghc-bignum at the point when it is trying to run: $ "inplace/bin/ghc-stage1" -v1 \ -hisuf hi \ -osuf o \ -hcsuf hc \ -static -O0 -H64m -Wall -fllvm-fill-undef-with-garbage -Werror \ -this-unit-id base-4.16.0.0 \ -hide-all-packages -package-env - -i \ -ilibraries/base/. \ -ilibraries/base/dist-install/build \ -Ilibraries/base/dist-install/build \ -ilibraries/base/dist-install/build/./autogen \ -Ilibraries/base/dist-install/build/./autogen \ -Ilibraries/base/include \ -Ilibraries/base/dist-install/build/include \ -optP-include \ -optPlibraries/base/dist-install/build/./autogen/cabal_macros.h \ -package-id ghc-bignum-1.0 \ -package-id ghc-prim-0.8.0 \ -package-id rts \ -this-unit-id base \ -Wcompat -Wnoncanonical-monad-instances \ -XHaskell2010 -O \ -dcore-lint -dno-debug-output \ -no-user-package-db \ -rtsopts \ -Wno-trustworthy-safe -Wno-deprecated-flags -Wnoncanonical-monad-instances \ -outputdirlibraries/base/dist-install/build \ -dynamic-too \ -c libraries/base/./GHC/Exception/Type.hs-boot \ -o libraries/base/dist-install/build/GHC/Exception/Type.o-boot \ -dyno libraries/base/dist-install/build/GHC/Exception/Type.dyn_o-boot My best guess is that the problem command fires via libraries/base/dist-install/package-data.mk which is created by cabal, and things get rather complicated from there... -- Viktor.