bam @0.5.1: clang: error: unknown argument: '-j1'

[ryandesign (Ryan Carsten Schmidt)]

​https://build.macports.org/builders/ports-12_arm64-builder/builds/101347/steps/install-port/logs/stdio

compiling using /usr/bin/clang...
clang: error: unknown argument: '-j1'
Command failed:  cd "/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_bam/bam/work/bam-0.5.1" && ./make_unix.sh -j1 
Exit code: 1

This may be fixed in the next version of MacPorts due to [2fafcefd752f326433e80636867be76775bb3531/macports-base].