don't know how to build these paths:
  /nix/store/cy4v6c8vv1jvr2339bxwmxzh0lzp09ji-clang21-riscv64-linux.drv
warning: ignoring the client-specified setting 'store', because it is a restricted setting and you are not a trusted user
platform: riscv64-linux binfmt=false
unpack: /nix/store/f0zxrgwyz7yx997a2sq4a2fkmcxppjvl-llvm-project-21.1.8.src
setup: cmake
cmake-probes: cold
debug: 4 files, 1.3 GB
launcher: bin/c-index-test -> {root}/bin/.c-index-test
launcher: bin/clang-tblgen -> {root}/bin/.clang-tblgen
exports: {"name":"clang21","includeDirs":["include"],"libDirs":["lib"],"libs":["clang-cpp","clang"],"pkgconfigDirs":[],"aclocalDirs":[],"env":{},"propagate":[]}
jig: cc cached=0/1043 (0%) no-daemon=1042 linked=1
uncached: no-daemon	-fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dt
uncached: no-daemon	-DCLANG_EXPORTS -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/build/build/lib/Driver -I/build/source/clang/lib/Driver -I/build/source/clang/include -I/build/build/include -fPIC -fno-semantic-interpos
uncached: no-daemon	-DCLANG_EXPORTS -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/build/build/lib/StaticAnalyzer/Core -I/build/source/clang/lib/StaticAnalyzer/Core -I/build/source/clang/include -I/build/build/include -f
uncached: no-daemon	-DCLANG_EXPORTS -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/build/build/lib/CodeGen -I/build/source/clang/lib/CodeGen -I/build/source/clang/include -I/build/build/include -fPIC -fno-semantic-interp
uncached: no-daemon	-DCLANG_EXPORTS -DEXPERIMENTAL_KEY_INSTRUCTIONS -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/build/build/lib/Sema -I/build/source/clang/lib/Sema -I/build/source/clang/include -I/build/build/include -fPIC -fno-semantic-interpositio