A legacy makefile that I'm trying to understand has -Wl,-z,origin,-rpath,'$ORIGIN/../lib'
OK, I see -Wl means the following are linker options; the commas will be replaced with spaces.
The manpage for the GNU ld mysteriously only says:
-z keyword
The recognized keywords are:
:
:
origin
Marks the object may contain $ORIGIN.
Likewise the next option -rpath (relative path?) contains this $ORIGIN suggesting it's some kind of key word but $ORIGIN is not otherwise mentioned in the ld man page.