git-branchless: add LA64 and mips64el-like to FAIL_ARCH

Author: KexyBiscuit

app-utils/git-branchless/autobuild/defines

@@ -6,3 +6,16 @@ BUILDDEP="rustc llvm"
 
 USECLANG=1
 ABSPLITDBG=0
+
+# FIXME: Too many dependencies on old versions of nix...
+# ... which has no LoongArch support until 0.27.0
+# https://github.com/nix-rust/nix/pull/2045
+#
+# FIXME: on mips64el-like architectures, both CFLAGS and CXXFLAGS contain -fPIC, but...
+# error: linking with `clang` failed: exit status: 1
+#   |
+#   = note: ld.lld: error: relocation R_MIPS_64 cannot be used against symbol 'DW.ref.rust_eh_personality'; recompile with -fPIC
+#           >>> defined in /usr/lib64/rustlib/mips64el-unknown-linux-gnuabi64/lib/libstd-6dcaeb4e3195ef4c.rlib(std-6dcaeb4e3195ef4c.std.fc0db18c60d19c82-cgu.0.rcgu.o)
+#           >>> referenced by std.fc0db18c60d19c82-cgu.0
+#           >>>               std-6dcaeb4e3195ef4c.std.fc0db18c60d19c82-cgu.0.rcgu.o:(.eh_frame+0x37B3) in archive /usr/lib64/rustlib/mips64el-unknown-linux-gnuabi64/lib/libstd-6dcaeb4e3195ef4c.rlib
+FAIL_ARCH="(loongarch64|loongson3|mips64r6el)"