[GHC] #7234: Linker spews useless error message and failes.

[GHC]

#7234: Linker spews useless error message and failes.
------------------------------+---------------------------------------------
 Reporter:  timthelion        |          Owner:                  
     Type:  bug               |         Status:  new             
 Priority:  normal            |      Component:  Build System    
  Version:  7.4.2             |       Keywords:                  
       Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
  Failure:  None/Unknown      |       Testcase:                  
Blockedby:                    |       Blocking:                  
  Related:                    |  
------------------------------+---------------------------------------------
 This is with ImplicitCAD as installed by way of

 {{{
 git clone https://github.com/colah/ImplicitCAD.git
 cd ImplicitCad
 cabal install
 }}}

 All other packages work.  Only ImplicitCAD is broken.

 {{{
 [timothy at timothy chassi]$ ghc f.hs
 [1 of 1] Compiling Main             ( f.hs, f.o )
 Linking f ...
 /home/timothy/.cabal/lib/implicit-0.0.2/ghc-7.4.2/libHSimplicit-0.0.2.a(PolylineFormats.o):
 In function `sVY1_info':
 (.text+0x4322): undefined reference to
 `implicitzm0zi0zi2_GraphicsziImplicitziExportziTextBuilderUtils_zdwbuildTruncFloat_info'
 /home/timothy/.cabal/lib/implicit-0.0.2/ghc-7.4.2/libHSimplicit-0.0.2.a(PolylineFormats.o):
 In function `sVY2_info':
 (.text+0x439a): undefined reference to
 `implicitzm0zi0zi2_GraphicsziImplicitziExportziTextBuilderUtils_zdwbuildTruncFloat_info'
 /home/timothy/.cabal/lib/implicit-0.0.2/ghc-7.4.2/libHSimplicit-0.0.2.a(PolylineFormats.o):
 In function `rUUt_srt':
 (.data+0x910): undefined reference to
 `implicitzm0zi0zi2_GraphicsziImplicitziExportziTextBuilderUtils_zdwbuildTruncFloat_closure'
 collect2: error: ld returned 1 exit status

 }}}

 {{{
 [timothy at timothy chassi]$ cat f.hs
 import Graphics.Implicit
 main=do
  writeSTL 0 "foo.stl" $ rect3R 0 (0,0,0) (1,1,1)
  return ()

 }}}

 {{{
 [timothy at timothy chassi]$ ghc -v
 Glasgow Haskell Compiler, Version 7.4.2, stage 2 booted by GHC version
 7.4.1
 Using binary package database:
 /usr/lib/ghc-7.4.2/package.conf.d/package.cache
 Using binary package database:
 /home/timothy/.ghc/x86_64-linux-7.4.2/package.conf.d/package.cache
 hiding package stm-2.3 to avoid conflict with later version stm-2.4
 hiding package her-lexer-0.1 to avoid conflict with later version her-
 lexer-0.1.1
 wired-in package ghc-prim mapped to ghc-
 prim-0.2.0.0-7d3c2c69a5e8257a04b2c679c40e2fa7
 wired-in package integer-gmp mapped to integer-
 gmp-0.4.0.0-af3a28fdc4138858e0c7c5ecc2a64f43
 wired-in package base mapped to
 base-4.5.1.0-6e4c9bdc36eeb9121f27ccbbcb62e3f3
 wired-in package rts mapped to builtin_rts
 wired-in package template-haskell mapped to template-
 haskell-2.7.0.0-2bd128e15c2d50997ec26a1eaf8b23bf
 wired-in package dph-seq not found.
 wired-in package dph-par not found.
 Hsc static flags: -static
 *** Deleting temp files:
 Deleting:
 *** Deleting temp dirs:
 Deleting:
 ghc: no input files
 Usage: For basic information, try the `--help' option.
 [timothy at timothy chassi]$

 }}}

 I know that this kind of bug report isn't very useful, as it's usually
 system specific :( .  But you need to be aware that there are kinks.

 Proposed fix:

 When ld returns 1, post an error message with suggestions as to how to fix
 the error.  So far, I've received link errors in two cases.  Once,
 deleting the .o file fixed it.  This time, I have yet to figure out a work
 around.  Once I do, I will post the work around to this bug report.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7234>
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