cctools-port 949.0.1 broke various builds on macOS

[r-burns]

Describe the bug
Ruby configure step has been failing on darwin since 3c6bd61 with the following error:

checking whether CFLAGS is valid... yes
checking whether LDFLAGS is valid... no
configure: error: something wrong with LDFLAGS=""

This appears to be due to the new linker warning ld: warning: passed two min versions (10.12.0, 10.12) for platform macOS, as adding LDFLAGS="-Wl,-w" to ruby allows it to build successfully.

git bisect log:

git bisect start
# bad: [92c96b799528442f6799f829d11602786689b28e] pkgs-lib/tests/formats: fix whitespace after PR #100372
git bisect bad 92c96b799528442f6799f829d11602786689b28e
# good: [53ce0bfc904a8e0dbe0d81cc1624815d4d8a038f] Merge pull request #95592 from risicle/ris-flink-1.11.1
git bisect good 53ce0bfc904a8e0dbe0d81cc1624815d4d8a038f
# good: [4c6dad5e826929ecd125472b4608b493b3efc24e] lsd: add maintainer
git bisect good 4c6dad5e826929ecd125472b4608b493b3efc24e
# good: [6d174dd5e0650073971a75efec218c79cbce951f] linux: Remove 5.7
git bisect good 6d174dd5e0650073971a75efec218c79cbce951f
# bad: [27143f8e022cbc9e0a480c3b89d757920aef55f6] nodejs-12_x: 12.18.4 -> 12.19.0
git bisect bad 27143f8e022cbc9e0a480c3b89d757920aef55f6
# bad: [0a5be167a3b5808c2b42a8660cf015c79965b204] Merge pull request #97098 from volth/cpan2nix-2020-09-04
git bisect bad 0a5be167a3b5808c2b42a8660cf015c79965b204
# good: [e9f7e3a97350133bdcd699ef44fbbf9d5678968b] [cpan2nix] perlPackages.PPIxRegexp: 0.072 -> 0.074
git bisect good e9f7e3a97350133bdcd699ef44fbbf9d5678968b
# good: [f728bea688227536a73b382ec1a2afb8be2854d0] [cpan2nix] perlPackages.CatalystViewTT: 0.44 -> 0.45
git bisect good f728bea688227536a73b382ec1a2afb8be2854d0
# bad: [5e68d203f3f8abf8f928fb6788487b83e3a0e8ec] opencv2: mark as broken
git bisect bad 5e68d203f3f8abf8f928fb6788487b83e3a0e8ec
# bad: [9112a9d882ed58d1823db8558d0bc8ceb2f33a5e] Merge pull request #93596 from obsidiansystems/ios-13
git bisect bad 9112a9d882ed58d1823db8558d0bc8ceb2f33a5e
# good: [1ca7c6e76a5138f7f0f3661c4d372fe15c0905c2] Merge pull request #97485 from marsam/update-nodejs-14_x
git bisect good 1ca7c6e76a5138f7f0f3661c4d372fe15c0905c2
# bad: [95eabdfd5f6197c83e9e5f53ddb65dbbea3c13fd] xcode/sdk-pkgs.nix: set -platform_version in addition to -miphoneos-version-min
git bisect bad 95eabdfd5f6197c83e9e5f53ddb65dbbea3c13fd
# bad: [3c6bd61560d042ce1e366989b92b615dfa1dffb3] darwin.cctools: 927.0.2 -> 949.0.1
git bisect bad 3c6bd61560d042ce1e366989b92b615dfa1dffb3
# good: [39c536c8db4e0982f89b67a194cd36ba9f4fbdd5] darwin.libtapi: update, fix installTargets
git bisect good 39c536c8db4e0982f89b67a194cd36ba9f4fbdd5
# first bad commit: [3c6bd61560d042ce1e366989b92b615dfa1dffb3] darwin.cctools: 927.0.2 -> 949.0.1

Further bisection on the cctools-port repo itself is unproductive, simply leading to the mass update tpoechtrager/cctools-port@466063c See #101330 (comment) for the offending code in cctools.

Hydra build
https://hydra.nixos.org/build/128219205

Notify maintainers
cctools: @matthewbauer
ruby: @vrthra @manveru @marsam

[SuperSandro2000]

Diff if someone needs it quickly.

I couldn't find the root cause and it is breaking a lot for darwin so we maybe should just take this fix.

diff --git a/pkgs/development/interpreters/ruby/default.nix b/pkgs/development/interpreters/ruby/default.nix
index 1fa5ea0aecfb..8fbbdefb1afc 100644
--- a/pkgs/development/interpreters/ruby/default.nix
+++ b/pkgs/development/interpreters/ruby/default.nix
@@ -126,6 +126,7 @@ let
             "--with-out-ext=tk"
             # on yosemite, "generating encdb.h" will hang for a very long time without this flag
             "--with-setjmp-type=setjmp"
+            # fix error after upgrading cctools-port to 949.0.1
+            # https://github.com/NixOS/nixpkgs/issues/101330
+            "LDFLAGS=-Wl,-w"
           ]
           ++ op (stdenv.hostPlatform != stdenv.buildPlatform)
              "--with-baseruby=${buildRuby}";

[r-burns]

@jonringer I think this is also causing haskellPackages.trifecta to fail which is blocking the unstable channel 👀 https://hydra.nixos.org/build/129070963/nixlog/1

It seems to me that there is a deeper issue here involving the new cctools and how they are being invoked:

• Why are two min versions being passed? Can we avoid that?
• If not, is it feasible going forward to keep patching this warning out of cctools?

[r-burns]

I think the correct ping is @NixOS/darwin-maintainers but I don't seem to have the clearance ;)

[zowoq]

cc @NixOS/darwin-maintainers

[r-burns]

I'm currently testing out this patch to disable the warning - ruby is working, haskellPackages.trifecta still building also works. Not sure if this is the right solution though, if the multiple versions being passed in the first place are the root problem.

diff --git a/cctools/ld64/src/ld/Options.cpp b/cctools/ld64/src/ld/Options.cpp
index 5b8c755..1b8ebf8 100644
--- a/cctools/ld64/src/ld/Options.cpp
+++ b/cctools/ld64/src/ld/Options.cpp
@@ -3187,8 +3187,6 @@ void Options::parse(int argc, const char* argv[])
 				}
 				if (fPlatforms.contains(info->platform)) {
 					std::string existingVersionStr = getVersionString32(fPlatforms.minOS(info->platform));
-					warning("passed two min versions (%s, %s) for platform %s. Using %s.",
-							existingVersionStr.c_str(), versStr, info->printName, versStr);
 					fPlatforms.updateMinVersion(info->platform, minVersValue);
 					fPlatforms.updateSDKVersion(info->platform, SDKValue);
 				} else {
@@ -3210,8 +3208,6 @@ void Options::parse(int argc, const char* argv[])
 				}
 				if (fPlatforms.contains(info->platform)) {
 					std::string existingVersionStr = getVersionString32(fPlatforms.minOS(info->platform));
-					warning("passed two min versions (%s, %s) for platform %s. Using %s.",
-							existingVersionStr.c_str(), versStr, info->printName, versStr);
 					fPlatforms.updateMinVersion(info->platform, value);
 				} else {
 					fPlatforms.insert(ld::PlatformVersion(info->platform, value));

[zowoq]

Seems that the root cause is mentioned in the cctools PR: #93596 (comment)

[r-burns]

I guess I'm still not really clear on who's in the wrong here. Is cctools being overly strict by adding this warning? Or is clang overstepping its role by auto-adding extra flags?

[zowoq]

I think #93596 (comment) means that this is the problem now that as clang is also adding the args:

nixpkgs/pkgs/build-support/bintools-wrapper/default.nix

Line 255 in 61d82f0

echo "-macosx_version_min 10.12 -sdk_version 10.12 -no_uuid" >> $out/nix-support/libc-ldflags-before

[zowoq]

oops forgot the ping

cc @thefloweringash