Clang attempts to guess file names based on the OS and distro (yes!),
but unfortunately, that doesn't work for us.

This patch makes it easy to insert libc's $libdir so that Clang passes the
correct absolute file name of crt1.o etc. to 'ld'.  It also disables all
the distro-specific stuff and removes the hard-coded FHS directory names
to make sure Clang also works on non-GuixSD systems.

This patch makes slight adjustments over "clang-libc-search-path.patch" for
changes in clang 3.8.

--- cfe-3.8.0.src/lib/Driver/ToolChains.cpp
+++ cfe-3.8.0.src/lib/Driver/ToolChains.cpp
@@ -3661,6 +3661,9 @@
                          GCCInstallation.getTriple().str() + "/bin")
                        .str());
 
+  // Comment out the distro-specific tweaks so that they don't bite when
+  // using Guix on a foreign distro.
+#if 0
   Distro Distro = DetectDistro(D, Arch);
 
   if (IsOpenSUSE(Distro) || IsUbuntu(Distro)) {
@@ -3702,6 +3705,7 @@
 
   if (IsOpenSUSE(Distro))
     ExtraOpts.push_back("--enable-new-dtags");
+#endif
 
   // The selection of paths to try here is designed to match the patterns which
   // the GCC driver itself uses, as this is part of the GCC-compatible driver.
@@ -3771,14 +3775,12 @@
     addPathIfExists(D, D.Dir + "/../" + OSLibDir, Paths);
   }
 
-  addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
-  addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
-  addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
-  addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
-
   // Try walking via the GCC triple path in case of biarch or multiarch GCC
   // installations with strange symlinks.
   if (GCCInstallation.isValid()) {
+    // The following code would end up adding things like
+    // "/usr/lib/x86_64-unknown-linux-gnu/../../lib64" to the search path.
+#if 0
     addPathIfExists(D,
                     SysRoot + "/usr/lib/" + GCCInstallation.getTriple().str() +
                         "/../../" + OSLibDir,
@@ -3791,6 +3793,7 @@
                              BiarchSibling.gccSuffix(),
                       Paths);
     }
+#endif
 
     // See comments above on the multilib variant for details of why this is
     // included even from outside the sysroot.
@@ -3815,8 +3818,9 @@
   if (StringRef(D.Dir).startswith(SysRoot))
     addPathIfExists(D, D.Dir + "/../lib", Paths);
 
-  addPathIfExists(D, SysRoot + "/lib", Paths);
-  addPathIfExists(D, SysRoot + "/usr/lib", Paths);
+  // Add libc's lib/ directory to the search path, so that crt1.o, crti.o,
+  // and friends can be found.
+  addPathIfExists(D, "@GLIBC_LIBDIR@", Paths);
 }
 
 bool Linux::HasNativeLLVMSupport() const { return true; }
inputs-self-contained.scm?id=3ff0a976e8f9e3792b39b5968cb9ff066eb4ba60&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-03-10 08:49:48 +0100'>2021-03-10</span></td><td><a href='/guix/commit/build-aux/check-final-inputs-self-contained.scm?id=76bea3f8bcd951ded88dfb7f8cad5bc3e5a1701f'>ci: Remove hydra support.</a><span class='msg-avail'>...<span class='msg-tooltip'>This removes hydra support to use Cuirass as the only continuous integration
system.

* build-aux/hydra/gnu-system.scm: Remove it.
* build-aux/hydra/guix-modular.scm: Ditto.
* build-aux/hydra/guix.scm: Ditto.
* build-aux/cuirass/hydra-to-cuirass.scm: Ditto.
* Makefile.am (EXTRA_DIST): Update it.
(hydra-jobs.scm): Remove it.
(cuirass-jobs.scm): Update it.
* build-aux/hydra/evaluate.scm: Move it to ...
* build-aux/cuirass/evaluate.scm: ... here.
* build-aux/cuirass/guix-modular.scm: Remove it.
* build-aux/cuirass/gnu-system.scm: Ditto.
* guix/packages.scm (%hydra-supported-systems): Rename it to ...
(%cuirass-supported-systems): ... this variable.
* build-aux/check-final-inputs-self-contained: Adapt it.
* etc/release-manifest.scm: Ditto.
* gnu/ci.scm (package-&gt;alist): Remove it.
(derivation-&gt;job): New procedure.
(package-job, package-cross-job, cross-jobs, image-jobs, system-test-jobs,
tarball-jobs): Use it.
(guix-jobs): New procedure.
(hydra-jobs): Rename it to ...
(cuirass-jobs): ... this procedure.
</span></span></td><td>Mathieu Othacehe</td></tr>