why bazel not search system include paths - c++

Question

The error is
.../demo.cc:5:10: fatal error: 'city.h' file not found
#include <city.h>
cityhash is installed by brew install cityhash.
city.h can be found in /usr/local/include.
And, it is actually in the search path of clang.
$ clang -E -xc++ - -v
Apple LLVM version 10.0.1 (clang-1001.0.46.3)
Target: x86_64-apple-darwin18.2.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.14.0 -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -E -disable-free -disable-llvm-verifier -discard-value-names -main-file-name - -mrelocation-model pic -pic-level 2 -mthread-model posix -mdisable-fp-elim -fno-strict-return -masm-verbose -munwind-tables -target-sdk-version=10.14 -target-cpu penryn -dwarf-column-info -debugger-tuning=lldb -target-linker-version 450.3 -v -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/10.0.1 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -I/usr/local/include -stdlib=libc++ -Wno-atomic-implicit-seq-cst -Wno-framework-include-private-from-public -Wno-atimport-in-framework-header -Wno-quoted-include-in-framework-header -fdeprecated-macro -fdebug-compilation-dir /Users/formath/git/mlp -ferror-limit 19 -fmessage-length 202 -stack-protector 1 -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fobjc-runtime=macosx-10.14.0 -fcxx-exceptions -fexceptions -fmax-type-align=16 -fdiagnostics-show-option -fcolor-diagnostics -o - -x c++ -
clang -cc1 version 10.0.1 (clang-1001.0.46.3) default target x86_64-apple-darwin18.2.0
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/v1"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/local/include"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/10.0.1/include
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/System/Library/Frameworks (framework directory)
My Bazel version is 1.1.0.
I have saw a same question which is not fixed right now.
https://github.com/bazelbuild/bazel/issues/5391

Answer 1

As a workaround you could add a cc_library for a new_local_repository that wraps a view on /usr/local.
In your WORKSPACE file define a new_local_repository with the path attribute set to /usr/local and the build_file pointing to a BUILD file local to the workspace, for example:
# WORKSPACE
new_local_repository(
name = "usr_local",
path = "/usr/local",
build_file = "third_party/usr_local.BUILD",
)
The third_party/usr_local.BUILD file could have different rules for different libraries you want to wrap. For cityhash you could do something like this (I don't know the structure of the cityhash library, so I'm guessing here about the .so):
# third_party/usr_local.BUILD
cc_library(
name = "cityhash",
hdrs = glob(["include/cityhash/**"]),
srcs = [
"lib64/cityhash.so",
],
includes = [
"include/cityhash",
],
visibility = ["//visibility:public"],
)
Notice that the paths will be relative to the new local repository location (so in this case /usr/local).
Finally in your BUILD file you can reference the cityhash targetu using:
# BUILD
cc_binary(
name = "main",
srcs = [
"main.cc",
],
deps = [
"#usr_local//:cityhash",
],
)
Hope this helps.