https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87243
Bug ID: 87243 Summary: FSF needs to use xcrun on darwin18 to find system headers in SDK Product: gcc Version: 9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: howarth.at.gcc at gmail dot com Target Milestone: --- The Xcode 10 release on 10.14 deprecates the presence of the system headers in / such that the Command Line Tools package no longer installs a /usr/include directory. While Apple is providing a fall back header package to install the SDK in /, this will be dropped in a future macOS release. The Apple clang compilers aren't explicitly patched to address this issue. Rather the compiler stubs in /usr/bin execute the compilers in the Xcode application and the Command Line Tools via the xcrun program which sets the SDKROOT environmental appropriately. Since installing compiler wrappers to do this for FSF gcc would be problematic for the other targets, the better approach would be to have the header search path enhanced to default to -iwithsysroot `xcrun --sdk macosx --show-sdk-path` for FSF gcc.