Adding a plugin with TH code causes segfault on linux

[hamishmack]

Here is a smallish example to reproduce the issue:

git clone https://github.com/hamishmack/plugin-test.git
nix-shell
./test.sh

Not sure why, but it seems not to crash on macOS.

GDB back trace (I'll try to get one with debug info)

(gdb) bt
#0  0x00007ffff320081c in s1tNrj_info () from /nix/store/xirww4ji37j6gbx7slb13n8qbpcysdck-ghc-8.6.5-lib-ghc/lib/x86_64-linux-ghc-8.6.5/libHSghc-8.6.5-EJczqCQztt0zzT7IjTfYb-ghc8.6.5.so
haskell/ghcide#1  0x0000000000000000 in ?? ()

strace output ends with

write(1, "Step 6/6: Type checking the file"..., 34Step 6/6: Type checking the files
) = 34
futex(0x109b7ec, FUTEX_WAIT_PRIVATE, 0, NULL) = 0
futex(0x109b7f0, FUTEX_WAIT_PRIVATE, 2, NULL) = 0
futex(0x109b7f0, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0x7f37e8236cc8, FUTEX_WAIT_PRIVATE, 2, NULL) = 0
futex(0x7f37e8236cc8, FUTEX_WAKE_PRIVATE, 1) = 0
mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f3759ffc000
mprotect(0x7f3759ffd000, 8388608, PROT_READ|PROT_WRITE) = 0
clone(child_stack=0x7f375a7fbfb0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tid=[7230], tls=0x7f375a7fc700, child_tidptr=0x7f375a7fc9d0) = 7230
openat(AT_FDCWD, "/proc/self/task/7230/comm", O_RDWR) = 71
write(71, "ghcide:w", 8               = 8
close(71)                               = 0
futex(0x109b7e8, FUTEX_WAIT_PRIVATE, 0, NULL) = ?
+++ killed by SIGSEGV (core dumped) +++
Segmentation fault (core dumped)

[mpickering]

@hamishmack Can you please update this issue with what you discovered about the effect of --enable-executable-dynamic?

[hamishmack]

Switching off --enable-executable-dynamic on ghcide seems to fix the segfault.

I have added a flag to the test case here that can be used to switch --enable-executable-dynamic on and off.

[sloane-shark]

Any workarounds for this? Trying to make use of polysemy-plugin, which seems to trigger the same issue?

[fendor]

I have been using ghcide with polysemy-plugin before, seems to be working for me

[cocreature]

@matthewess Have you tried linking dynamically like @hamishmack suggested above?

[sloane-shark]

@cocreature should have mentioned, I’m using ghcide-nix so i believe id have to use the fork they used in their example. for now i’m just not using plugins

[jneira]

Not sure if haskell/ghcide#836 could help with this, @matthewess @hamishmack could you give a try?

[jneira]

will close this one optimistically in a few days