I can confirm that the second proposed solution of passing -Wl,-no_compact_unwind to the linkage of the g++.dg/torture/stackalign/eh-vararg-2.C test cases eliminates the execution error on x86_64-apple-darwin10 so that option works. This leads to a dejagnu question. I want to do a quick and dirty test to see that -Wl,-no_compact_unwind suppresses all of the regressions that appeared at r147995, however I can't puzzle out how to formulate...
make -k check RUNTESTFLAGS="--target_board=unix'{-Wl,-no_compact_unwind}'" such that -Wl,-no_compact_unwind is interpreted as a single run with one flag being passed (ie not one run with -Wl and one run with -no_compact_unwind). Any ideas? Jack