[GHC] #11042: Template Haskell / GHCi does not respect extra-lib-dirs

[GHC]

#11042: Template Haskell / GHCi does not respect extra-lib-dirs
-------------------------------------+-------------------------------------
        Reporter:  mboes             |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash                              |            Test Case:
      Blocked By:  11238             |             Blocking:
 Related Tickets:  #10458 #5289      |  Differential Rev(s):  Phab:D5170
  #12753                             |
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ericson2314):

 That patch seems...odd to me. I think we might have a simpler problem:

 I did on nixos unstable (but I think 18.09 would also work)
  - clone recentish Cabal
  - `nix-shell -p 'haskellPackages.ghcWithPackages (p: [ p.zlib ])' -p zlib
 -p haskellPackages.happy -p haskellPackages.alex`
  - `new-configure -O0 --enable-tests --extra-lib-
 dirs=/nix/store/...-zlib-1.2.11/lib`
  - `cabal new-repl cabal-install`

 `-L` from `--extra-lib-dirs` did make it to ghci, but it fails with

 {{{
 <command line>: can't load .so/.DLL for: libz.so (libz.so: cannot open
 shared object file: No such file or directory)
 }}}

 and `ghci -v` gives me

 {{{
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name libz.so
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name liblibz.so
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name z.lib
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name libz.lib
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name libz.dll.a
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name z.dll.a
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name libz.a
 *** gcc:
 /nix/store/10yq7kwlvbc6h658izmrlsspry1g9f3c-gcc-wrapper-7.3.0/bin/cc -fno-
 stack-protector -DTABLES_NEXT_TO_CODE
 -B/home/jcericson/.cabal/store/ghc-8.4.3/digest-0.0.1.2-14fe411601bb13fe646394df438bbd46ddfbff1cdb12e63d463c3cc847a007ff/lib
 --print-file-name z.a
 Loading package digest-0.0.1.2 ... *** Deleting temp files:
 Deleting:
 *** Deleting temp dirs:
 }}}

 There's plenty to minimize and control here (e.g.
 `~/.cabal/store/ghc-8.4.3/package.db` populated in different nix-shells),
 but I want to ask the simple check, if ghc is looking up libz.so, why
 isn't it using -L? (Maybe the directories listed in the package db
 override it?)

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11042#comment:31>
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