abseil-20240116.2_1: fails to build on macOS 10.14.6/Xcode 11.3.1 due to SDKROOT being set to MacOSX10.14.sdk

[jbflanman]

While trying to run 'port upgrade outdated' abseil-20240116.2_1 repeatedly fails even after 'port clean abseil' and 'port clean --work abseil'. Digging into the main.log I find two errors:

:info:build /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_abseil/abseil/work/abseil-cpp-20240116.2/absl/hash/internal/hash.h:602:53: error: 'path' is unavailable: introduced in macOS 10.15
:info:build               std::is_same_v<Path, std::filesystem::path>>>
:info:build                                                     ^
:info:build /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/filesystem:739:24: note: 'path' has been explicitly marked unavailable here
:info:build class _LIBCPP_TYPE_VIS path {
:info:build                        ^
:info:build In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_abseil/abseil/work/abseil-cpp-20240116.2/absl/hash/internal/hash.cc:15:
:info:build /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_abseil/abseil/work/abseil-cpp-20240116.2/absl/hash/internal/hash.h:609:61: error: 'hash_value' is unavailable: introduced in macOS 10.15
:info:build   return H::combine(std::move(hash_state), std::filesystem::hash_value(path));
:info:build                                                             ^
:info:build /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/filesystem:1195:8: note: 'hash_value' has been explicitly marked unavailable here
:info:build size_t hash_value(const path& __p) noexcept;
:info:build        ^

At the begining of the main.log I see this:

:debug:extract CPATH='/opt/local/include'
:debug:extract DEVELOPER_DIR='/Library/Developer/CommandLineTools'
:debug:extract LIBRARY_PATH='/opt/local/lib'
:debug:extract MACOSX_DEPLOYMENT_TARGET='10.14'
:debug:extract MACPORTS_LEGACY_SUPPORT_DISABLED='1'
:debug:extract SDKROOT='/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk'

I have added export SDKROOT='/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk' to my .bash_profile and restarted terminal to no effect. I have both 10.14 and 10.15 SDK's.

Looks like this version of abseil needs a minimum sdk of 10.15.

[jbflanman]

main.log for abseil failure after both clean commands.