ghc 6.8.1 windows link issue ?

[Fernand]

Dear all,

Giving a try to GHC 6.8.1 under Windows, I stumble upon the following 
issue (yes, I'm struggling with HDirect), which did not occur with the 
6.6 version : the linking phase of my project fails with

$ C:/ghc/ghc-6.8.1/bin/ghc -o ihc.exe -fglasgow-exts -static -fvia-C 
-Rghc-timing -Wall -recomp       AbsHUtils.o AbstractH.o Attribute.o 
Bag.o [... lots of files, among which we have CoreUtils.o ...]

CoreUtils.o(.text+0x15066):ghc2436_0.hc: undefined reference to 
`containerszm0zi1zi0zi0_DataziGraph_stronglyConnComp_closure'
CoreUtils.o(.text+0x150b0):ghc2436_0.hc: undefined reference to 
`containerszm0zi1zi0zi0_DataziGraph_stronglyConnComp_closure'
CoreUtils.o(.text+0x1ac23):ghc2436_0.hc: undefined reference to 
`__stginit_containerszm0zi1zi0zi0_DataziGraph_'
IDLUtils.o(.text+0x6026):ghc768_0.hc: undefined reference to 
`containerszm0zi1zi0zi0_DataziGraph_stronglyConnComp_closure'
IDLUtils.o(.text+0x6070):ghc768_0.hc: undefined reference to 
`containerszm0zi1zi0zi0_DataziGraph_stronglyConnComp_closure'
IDLUtils.o(.text+0xc607):ghc768_0.hc: undefined reference to 
`__stginit_containerszm0zi1zi0zi0_DataziGraph_'
collect2: ld returned 1 exit status

Indeed, that symbol is undefined in the CoreUtils file :
$ nm CoreUtils.o | grep strongl
         U _containerszm0zi1zi0zi0_DataziGraph_stronglyConnComp_closure

As far as I understand, this is a reference to the Data.Graph function 
stronglyConnComp
(which can be seen in the « containers-0.1.0.0/Data/Graph.hi » interface 
file ; according to the haddock documentation of GHC, that function is 
indeed in the Data.Graph module, which is imported by the CoreUtils.lhs 
file). What is strange to me  is that

$ nm libHSghc.a | grep strongl

gives : 00000598 D _ghczm6zi8zi1_Digraph_stronglyConnComp_closure

which could explain why that function is not found.

May be I'm looking at the wrong file, I don't know much of the linking 
and name-mangling process at hand here (Digraph vs. DataziGraph ?). What 
I do not understand is what causes that issue, which seems to only 
concern the Data.Graph module so far.

Hopes this makes sense to you,

Sincerely yours,

Samuel