El Capitan, make check, DYLD_LIBRARY_PATH
It seems like DYLD_* only gets stripped out for “protected” binaries (I’m not sure exactly what that means, but apparently anything in /bin and /usr/bin for starters) However, if you copy /usr/bin/env to somewhere else, it gets to keep its DYLD_* stuff:

$ cp /usr/bin/env ~/Desktop; (DYLD_FOO=bar ~/Desktop/env)|grep DY
dyld: warning, unknown environment variable: DYLD_FOO
DYLD_FOO=bar


I think make always runs commands via /bin/sh, so you can’t set “dangerous” variables in the makefile and have them affect the commands, but maybe you could move the test into a shell script, set the environment variables inside the script, and then invoke the script from make. Though obviously, this won’t help you if the tests, in turn, rely on shell scripts (or if the things tested are shell scripts!) because then they’re going to invoke /bin/sh and lose the variables again...