gmp @6.3.0_0 configure error : configure: error: No usable m4 in $PATH or /usr/5bin

[nanigashi-uji (Nanigashi Uji)]

Under the environment at Sonoma 14.4 and Xcode15.3, even Xcode command line is installed, m4 can not be detected during "configure".

Corresponding part of outout from 'port -v install gmp'

...
checking for sstream... yes
checking for std::locale... yes
checking for suitable m4... configure: error: No usable m4 in $PATH or /usr/5bin (see config.log for reasons).
Command failed:  cd "......../gmp/work/gmp-6.3.0" && ./configure --prefix=/....  --host=applem1-apple-darwin23 --enable-cxx 
Exit code: 1
...

I found that the issue can be averted by adding the following lines in Ports file.

if {${os.platform} eq "darwin" && ${os.major} > 13 && [string match *clang* ${configure.compiler}]} {
    configure.env-append    M4=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/gm4
}