I have a personal project which on Linux involves building a shared library to be linked into a C++ program. The relevant portion of the Cabal file is as follows:
library
if os(windows)
ghc-options: -stubdir stub -o brassica-interop.a -static -optl-static -staticlib -Wall
else
ghc-options: -stubdir stub -o libbrassica-interop.so -dynamic -shared -fPIC -fPIE -flink-rts -Wall
hs-source-dirs: src
exposed-modules: BrassicaInterop
build-depends: base >= 4.7 && < 5
, brassica
, bytestring
, utf8-string >= 1.0 && < 1.1
default-language: Haskell2010
On GHC 9.2.5, this works without a problem. However, on upgrading to GHC 9.4.5, it gives the following error:
$ cabal build brassica-interop
Resolving dependencies...
Build profile: -w ghc-9.4.5 -O1
In order, the following will be built (use -v for more details):
- brassica-interop-0.0.3 (lib) (first run)
Preprocessing library for brassica-interop-0.0.3..
Building library for brassica-interop-0.0.3..
when making flags consistent: warning:
-dynamic-too is ignored when using -dynamic
[2 of 2] Linking libbrassica-interop.so [Flags changed]
/usr/bin/ld.gold: error: cannot open /<omitted>/brassica/dist-newstyle/build/x86_64-linux/ghc-9.4.5/brassica-interop-0.0.3/build/BrassicaInterop.dyn_o: No such file or directory
collect2: error: ld returned 1 exit status
`gcc' failed in phase `Linker'. (Exit code: 1)
Error: cabal: Failed to build brassica-interop-0.0.3.
I have no idea what’s happening here, or how to fix it. Does anyone have any ideas?
(Rereading the GHC User’s Guide, I saw it mention the --enable-shared Cabal option… alas, cabal build brassica-interop --enable-shared gives exactly the same result. However, cabal build brassica-interop --with-compiler=ghc-9.2.5 works, as mentioned above.)