`clashi` segfaults on macos

[pavel-demin]

The following simple test with clashi segfaults on macos 12:

% cat test.hs 
{-# LANGUAGE DataKinds, NoImplicitPrelude #-}
import Clash.Prelude
topEntity :: Signal System Bit -> Signal System Bit
topEntity = id

% clashi test.hs 
Clashi, version 1.4.6 (using clash-lib, version 1.4.6):
https://clash-lang.org/  :? for help
Loaded package environment from /Users/user/.ghc/x86_64-darwin-8.10.7/environments/default
[1 of 1] Compiling Main             ( test.hs, interpreted )
Ok, one module loaded.
*Main> signal = fromList [0, 1, 0, 1]
*Main> sampleN 4 $ topEntity signal
zsh: segmentation fault  clashi test.hs

It runs without problem with ghci:

% ghci test.hs
GHCi, version 8.10.7: https://www.haskell.org/ghc/  :? for help
Loaded package environment from /Users/user/.ghc/x86_64-darwin-8.10.7/environments/default
[1 of 1] Compiling Main             ( test.hs, interpreted )
Ok, one module loaded.
*Main> signal = fromList [0, 1, 0, 1]
*Main> sampleN 4 $ topEntity signal
[0,1,0,1]

[martijnbastiaan]

How did you install Clash? Did you follow the steps at https://clash-lang.org/install/macos/?

[pavel-demin]

I initially tried to follow the instructions and install Clash using stack, but I did not like the way stack handles versions of GHC and installs multiple copies of the compiler and libraries.

Currently, I am using ghcup to install GHC and cabal to install Clash. Here are the commands:

curl -L https://get-ghcup.haskell.org -o install-ghcup.sh
sh install-ghcup.sh
cabal install clash-ghc
cabal install --lib ghc-typelits-natnormalise ghc-typelits-extra ghc-typelits-knownnat clash-prelude

I use these commands on Debian 11 and macOS 12. On Debian 11 everything works, but on macOS 12 clashi segfaults.

[martijnbastiaan]

Right, we stopped recommending cabal install a while ago due to a host of issues associated with it. It still shouldn't segfault of course, but as a quick workaround; perhaps you could try a starter project and see if that works? Given that you've already installed stack, you can still use it to initialize the project but use cabal from there.

[pavel-demin]

Since I am only starting to experiment with macOS and Clash, I can remove my entire current installation and reinstall Clash following the instructions. I am now curious to see if this fixes the segfault problem.

[martijnbastiaan]

Good luck!

[pavel-demin]

Unfortunately, reinstalling Clash using stack does not fix the segfault problem.

I have reinstalled Clash with the following commands:

brew install haskell-stack
stack exec --package clash-ghc -- clash test.hs --vhdl

clashi still segfaults:

% cat test.hs 
{-# LANGUAGE DataKinds, NoImplicitPrelude #-}
import Clash.Prelude
topEntity :: Signal System Bit -> Signal System Bit
topEntity = id

% stack exec --package clash-ghc -- clashi test.hs 
Clashi, version 1.4.6 (using clash-lib, version 1.4.6):
https://clash-lang.org/  :? for help
[1 of 1] Compiling Main             ( test.hs, interpreted )
Ok, one module loaded.
*Main> signal = fromList [0, 1, 0, 1]
*Main> sampleN 4 $ topEntity signal
zsh: segmentation fault  stack exec --package clash-ghc -- clashi test.hs

[martijnbastiaan]

Perhaps you're affected by commercialhaskell/stack#5607?

[pavel-demin]

Thank you for the link. However, it does not look like exactly the same problem (different OS version, different CPU arch, different errors).

If I build clash-ghc via git clone and cabal build clash-ghc everything works. So, I cannot reproduce and debug the problem this way.

Looks like only clashi built via stack or cabal install has this problem. clashi built via cabal build works.

[pavel-demin]

Looks like my problem is similar to the one discussed in haskell/haskell-language-server#469 and ghc/ghc#19021.

The recommended workaround (enable executable-dynamic) works for me.

Here are the commands that I now use to install Clash:

curl -L https://get-ghcup.haskell.org -o install-ghcup.sh
sh install-ghcup.sh
sed -i.bak '/executable-dynamic/s/.*/executable-dynamic: True/' ~/.cabal/config
cabal install clash-ghc
cabal install --lib ghc-typelits-natnormalise ghc-typelits-extra ghc-typelits-knownnat clash-prelude

[martijnbastiaan]

Ah, this is something we set in cabal.project. This explains why you're seeing it for the Hackage distribution, but not when cloning the repository:

clash-compiler/cabal.project

Lines 25 to 27 in 9e7b9d3

	package clash-ghc
	ghc-options: +RTS -qn4 -A128M -RTS -j4
	executable-dynamic: True

[V0XNIHILI]

I had the same problem. Removed everything that I installed via HomeBrew and followed the steps from @pavel-demin.

Uninstalled previous installations via:

brew uninstall ghc haskell-stack cabal-install
rm -rf ~/.cabal
rm -rf ~/.ghc
rm -rf ~/.ghcup

Executing it via stack exec still fails, but I can now run it via clashi: