UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36

Steps to reproduce the problem:
1. Install and setup clang/clang++ on Gentoo system
2. Execute emerge chromium
3. Observe the result

What is the expected behavior?
Chromium should be installed

What went wrong?
Got compilation error:

[10114/25569] ../../../../../../../../../usr/bin/clang++ -MMD -MF clang_x64/obj/components/tracing/tools/proto_zero_plugin/proto_zero_plugin/proto_zero_plugin.o.d -DV8_DEPRECATION_WARNINGS -DUSE_UDEV -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DDISABLE_NACL -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DENABLE_MEDIA_ROUTER=1 -DCR_CLANG_REVISION=\"296320-1\" -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -I../.. -Iclang_x64/gen -I../../third_party/protobuf/src -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -funwind-tables -fPIC -pipe -fcolor-diagnostics -m64 -march=x86-64 -pthread -Wall -Wextra -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-covered-switch-default -Wno-deprecated-register -Wno-unneeded-internal-declaration -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-undefined-var-template -Wno-nonportable-include-path -Wno-address-of-packed-member -Wno-block-capture-autoreleasing -Wno-unused-lambda-capture -Wno-user-defined-warnings -O2 -fno-ident -fdata-sections -ffunction-sections -g0 -fvisibility=hidden -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -fvisibility-inlines-hidden -std=gnu++11 -fno-rtti -fno-exceptions -c ../../components/tracing/tools/proto_zero_plugin/proto_zero_plugin.cc -o clang_x64/obj/components/tracing/tools/proto_zero_plugin/proto_zero_plugin/proto_zero_plugin.o 
FAILED: clang_x64/obj/components/tracing/tools/proto_zero_plugin/proto_zero_plugin/proto_zero_plugin.o 
../../../../../../../../../usr/bin/clang++ -MMD -MF clang_x64/obj/components/tracing/tools/proto_zero_plugin/proto_zero_plugin/proto_zero_plugin.o.d -DV8_DEPRECATION_WARNINGS -DUSE_UDEV -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DDISABLE_NACL -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DENABLE_MEDIA_ROUTER=1 -DCR_CLANG_REVISION=\"296320-1\" -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -I../.. -Iclang_x64/gen -I../../third_party/protobuf/src -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -funwind-tables -fPIC -pipe -fcolor-diagnostics -m64 -march=x86-64 -pthread -Wall -Wextra -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-covered-switch-default -Wno-deprecated-register -Wno-unneeded-internal-declaration -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-undefined-var-template -Wno-nonportable-include-path -Wno-address-of-packed-member -Wno-block-capture-autoreleasing -Wno-unused-lambda-capture -Wno-user-defined-warnings -O2 -fno-ident -fdata-sections -ffunction-sections -g0 -fvisibility=hidden -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -fvisibility-inlines-hidden -std=gnu++11 -fno-rtti -fno-exceptions -c ../../components/tracing/tools/proto_zero_plugin/proto_zero_plugin.cc -o clang_x64/obj/components/tracing/tools/proto_zero_plugin/proto_zero_plugin/proto_zero_plugin.o 
/bin/sh: ../../../../../../../../../usr/bin/clang++: No such file or directory 

Did this work before? N/A 

Chrome version: 58.0.3029.81  Channel: n/a
OS Version: 4.9.12-aufs
Flash Version: adobe-flash 25.0.0.171

I think the key to this problem is the last line I posted:

    /bin/sh: ../../../../../../../../../usr/bin/clang++: No such file or directory 

On my system `which clang++` gives me:

    /usr/lib/llvm/4/bin/clang++

And Gentoo guys said it is the right place for clang++ and there's no other places it should be installed.