pkgsMusl.ocamlPackages.ocaml: -r and -pie may not be used together

[nomeata]

It used to be possible to build ocaml (it is possible on 20.09), but these days it fails with:

$ nix-build -A pkgsMusl.ocamlPackages.ocaml
…
../../ocamlopt.opt -g -nostdlib -I ../../stdlib -strict-sequence -principal -absname -w +a-4-9-40-41-42-44-45-48-66 -warn-error A -bin-annot -safe-string -strict-formats -I byte -function-sections -I native -pack -o native/dynlink_compilerlibs.cmx dynlink_compilerlibs/binutils.cmx dynlink_compilerlibs/config.cmx dynlink_compilerlibs/build_path_prefix_map.cmx dynlink_compilerlibs/misc.cmx dynlink_compilerlibs/identifiable.cmx dynlink_compilerlibs/numbers.cmx dynlink_compilerlibs/arg_helper.cmx dynlink_compilerlibs/clflags.cmx dynlink_compilerlibs/profile.cmx dynlink_compilerlibs/consistbl.cmx dynlink_compilerlibs/terminfo.cmx dynlink_compilerlibs/warnings.cmx dynlink_compilerlibs/local_store.cmx dynlink_compilerlibs/load_path.cmx dynlink_compilerlibs/int_replace_polymorphic_compare.cmx dynlink_compilerlibs/location.cmx dynlink_compilerlibs/longident.cmx dynlink_compilerlibs/docstrings.cmx dynlink_compilerlibs/syntaxerr.cmx dynlink_compilerlibs/ast_helper.cmx dynlink_compilerlibs/ast_mapper.cmx dynlink_compilerlibs/attr_helper.cmx dynlink_compilerlibs/builtin_attributes.cmx dynlink_compilerlibs/ident.cmx dynlink_compilerlibs/path.cmx dynlink_compilerlibs/primitive.cmx dynlink_compilerlibs/type_immediacy.cmx dynlink_compilerlibs/types.cmx dynlink_compilerlibs/btype.cmx dynlink_compilerlibs/subst.cmx dynlink_compilerlibs/predef.cmx dynlink_compilerlibs/datarepr.cmx dynlink_compilerlibs/cmi_format.cmx dynlink_compilerlibs/persistent_env.cmx dynlink_compilerlibs/env.cmx dynlink_compilerlibs/debuginfo.cmx dynlink_compilerlibs/lambda.cmx dynlink_compilerlibs/runtimedef.cmx dynlink_compilerlibs/instruct.cmx dynlink_compilerlibs/opcodes.cmx dynlink_compilerlibs/bytesections.cmx dynlink_compilerlibs/dll.cmx dynlink_compilerlibs/meta.cmx dynlink_compilerlibs/symtable.cmx dynlink_compilerlibs/asttypes.cmx dynlink_compilerlibs/parsetree.cmx dynlink_compilerlibs/outcometree.cmx dynlink_compilerlibs/cmo_format.cmx dynlink_compilerlibs/cmxs_format.cmx
/nix/store/30kg865p8ixsvblqypmfwzvqx72fglws-binutils-2.35.1/bin/ld: -r and -pie may not be used together
File "/build/ocaml-4.12.0/otherlibs/dynlink/native/dynlink_compilerlibs.cmx", line 1:
Error: Error during partial linking
make[4]: *** [Makefile:197: native/dynlink_compilerlibs.cmx] Error 2
make[4]: Leaving directory '/build/ocaml-4.12.0/otherlibs/dynlink'
make[3]: *** [Makefile:35: allopt] Error 2
make[3]: Leaving directory '/build/ocaml-4.12.0/otherlibs'
make[2]: *** [Makefile:896: otherlibrariesopt] Error 2
make[2]: Leaving directory '/build/ocaml-4.12.0'
make[1]: *** [Makefile:219: opt.opt] Error 2
make[1]: Leaving directory '/build/ocaml-4.12.0'
make: *** [Makefile:275: world.opt] Error 2
builder for '/nix/store/g8789fj4qsrzbicamlw772ldk9mp7hms-ocaml-4.12.0.drv' failed with exit code 2
error: build of '/nix/store/g8789fj4qsrzbicamlw772ldk9mp7hms-ocaml-4.12.0.drv' failed

I’ll try to bisect it…

[nomeata]

Bisecting points to 4e9dc46 by @utsl42. Nathan, do you have a hunch?

commit 4e9dc46dea0ef8cf15c567fa863796bb23099d0b
Author: Nathan Hawkins <[email protected]>
Date:   Sat Oct 24 22:34:50 2020 +0000

    stdenv: Fix hardening default for pkgsMusl to reenable -pie
    
    defaultHardeningFlags is set to enable pie for Musl, but is not
    actually used because the default is never put into
    NIX_HARDENING_ENABLE. That still works for cases other than Musl
    only because NIX_HARDENING_ENABLE is defaulted in the binutils and
    cc-wrapper setup-hook.sh scripts.

 pkgs/stdenv/generic/make-derivation.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

[nomeata]

Cargoculting what I saw in the GHC code, trying this right now:

diff --git a/pkgs/development/compilers/ocaml/generic.nix b/pkgs/development/compilers/ocaml/generic.nix
index d9853dd642a..ccf56140cf3 100644
--- a/pkgs/development/compilers/ocaml/generic.nix
+++ b/pkgs/development/compilers/ocaml/generic.nix
@@ -58,6 +58,9 @@ stdenv.mkDerivation (args // {
   ++ optional spaceTimeSupport (flags "--enable-spacetime" "-spacetime")
   ;
 
+  hardeningDisable = stdenv.lib.optional stdenv.targetPlatform.isMusl "pie";
+
+
   buildFlags = [ "world" ] ++ optionals useNativeCompilers [ "bootstrap" "world.opt" ];
   buildInputs = optional (!lib.versionAtLeast version "4.07") ncurses
     ++ optionals useX11 [ libX11 xorgproto ];

[nomeata]

Seems to work, fix in #124498

[utsl42]

There appear to be multiple linker bugs affecting at least Rust and GHC with Musl . Both bfd or gold had issues, gold seems a little worse. I would suggest trying lld, it may fix it.

[sternenseemann]

lld with gcc is currently not supported and I think last time I tried we can't build OCaml and all its dependencies with clang+lld fully yet…

[r-burns]

The second commit of #135619 ("match leading/trailing arguments") should fix this

[nomeata]

The second commit of #135619 ("match leading/trailing arguments") should fix this

That's great news!

[r-burns]

Fixed by #135619