Thanks Zubin! That looks very much on the mark. We might not need to change GHC after all if we can avoid calling the R runtime from Template Haskell [4].
[4] https://github.com/tweag/HaskellR/issues/369 On Tue, Nov 16, 2021 at 3:11 PM Zubin Duggal <zu...@well-typed.com> wrote: > A patch to run Template Haskell code in a forked thread was included in > ghc-8.10.6: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/5042 > > This was chosen as the only robust way to avoid reporting any > asynchronous exceptions thrown to the compilation process during TH > evaluation as a user error in TH code. If you cancel a compile by > throwing the compilation thread an exception, we don't want to catch > that error in GHC and report it as if the TH code had a regular > exception. By running the TH code in a forked thread and not sharing > the ThreadId, we ensure that any exception caught during the evaluation > of TH code either originated from the code itself or was thrown by the > RTS directly to the TH code (BlockedIndefinetelyOnMVar,... etc.). > > There may be alternative solutions to this or ways to make this > behaviour configurable. I would urge you to open an ticket on the GHC > tracker detailing your use case. > > On 21/11/16 11:26, Domínguez, Facundo wrote: > >Dear devs, > > > >I found recently that ghc-8.10.6 and ghc-8.10.7 might be behaving > >differently than previous compilers when running Template Haskell code. > > > >When upgrading HaskellR to use a newer ghc I found that it would work fine > >with ghc-8.10.4, but not ghc-8.10.6 or ghc-8.10.7. HaskellR, and the R > >runtime in particular, is sensitive to local state in the threads that are > >used to execute the runtime. HaskellR is arranging to run the R runtime > >when running TemplateHaskell splices, and this stopped working in MacOS > >with ghc-8.10.6. > > > >The error I got is not new. It comes from R and we would get it in ghci if > >we try to use HaskellR without passing the command line flag > >-fno-ghci-sandbox. But this is the first time we get the error when using > >TemplateHaskell. > > > >Does anyone know if there have been changes to the threads in which the TH > >splices are run? And were there any changes specific to TH in MacOS? > > > >Thanks in advance, > >Facundo > > > >[1] https://github.com/tweag/HaskellR/pull/368#issuecomment-968864170 > > >_______________________________________________ > >ghc-devs mailing list > >ghc-devs@haskell.org > >http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs > >
_______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
