Can't build 8.6.1-beta1 with debugging.

Mateusz Kowalczyk fuuzetsu at
Tue Aug 14 06:18:56 UTC 2018

Hi all,

I wanted to try our codebase with 8.6. I happened to already have ready so I started with that.

Compilation went well but I got a segfault when running a benchmark we have with profiling on. GDB told me the segfault was in stg_ap_ppppp_info in AutoApply.cmm which as I understand is generated. Strange but OK... I decided to try unprofiled with LLVM to see if some LLVM issue we had with current version (7.10.x) has gone away. Sadly I encountered a segfault during regular compilation (clean build, LLVM 6.0). I had no debugging symbols.

Next I decided to try the beta1 version. I copied mk/ into mk/ and added the following:

GhcDebugged = YES
GhcStage1HcOpts = -DDEBUG
GhcStage2HcOpts = -DDEBUG

I checked out the 8.6.1-beta1 tag then ran following.

fuuzetsu at rubin:~/programming/ghc$ echo $PREFIX
fuuzetsu at rubin:~/programming/ghc$ ./configure --prefix=$PREFIX && make -j4 && make install

After some time I was met with:

/usr/bin/ error: cannot find -lHSrts_thr_debug_p

Also a long chain of messages about undefined refs you can find at [1].

Considering I haven't touched any settings beyond adding debug flags, it surprised me a little that I can't build successfully. Please advise and feel free to ask for any specs.

uname -a:
Linux 4.15.0-30-generic #32~16.04.1-Ubuntu SMP Thu Jul 26 20:25:39 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


Mateusz K.

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