DYLD_LIBRARY_PATH environment variable is not forwarded to external command in Makefile on macOS

问题

I am debugging some test failures (make test) for a Perl module on macOS. I discovered that the problem seems to be that the environment variable DYLD_LIBRARY_PATH is not forwarded to an external command run from within the Makefile. Here is a minimal example:

.PHONY: all
all:
    @echo $$DYLD_LIBRARY_PATH

On Linux from the Bash shell, I can do (or rather replace DYLD_LIBRARY_PATH with LD_LIBRARY_PATH which is used for this purpose on Linux):

$ export DYLD_LIBRARY_PATH=bar
$ make
bar

However, if I run the same Makefile on macOS Catalina 10.15.5, the variable DYLD_LIBRARY_PATH is empty:

$ export DYLD_LIBRARY_PATH=bar
$ make
# [No output]

Any idea what is the reason for this difference?

来源：https://stackoverflow.com/questions/63629878/dyld-library-path-environment-variable-is-not-forwarded-to-external-command-in-m