RFC: Run the tests on julia-debug if JULIA_DEBUG==1

[garrison]

This modifies the Makefile so that make test and its siblings will use a debug build of julia if JULIA_DEBUG is set to 1. Previously, make test would always make a release build of julia and then run the tests, even if make had just made a debug build of julia due to JULIA_DEBUG being set.

[timholy]

👍 for this idea, though I'm not enough of a Makefile expert to count as a reviewer. I had the impression that make testall was running a debug build; or is that only on Travis?

[garrison]

From the looks of things, make testall will never use a debug build. In fact, if you compile julia in debug mode, running make test[all] will build "release" julia and overwrite your symlink to point to julia instead of julia-debug.

I just created a new (simpler, and more correct) patch, so would appreciate it if somebody with actual Makefile knowledge could review.

[pao]

I'd opt for @vtjnash or @ViralBShah for build system.

[garrison]

@timholy Actually we're both right: make testall will never use the debug build, but travis.yml bypasses that and calls julia-debug explicitly.

[timholy]

Thanks for finding that. I knew I had seen something like that somewhere.

[vtjnash]

lgtm

[vtjnash]

however, if you really want to have some fun with makefiles, replace JULIA_DEBUG=1 with ifneq (,$(findstring release,$(MAKECMDGOALS))) (interpretation: if the targets given on the command line by the user contained the string release), and let us know if that can be made to work.

https://www.gnu.org/software/make/manual/html_node/Goals.html

[garrison]

@vtjnash I'm not quite sure if I'm up for that now, and also I do not quite understand the benefit (could you please elaborate?). If I understand correctly, with that a debug build would be built by default, unless somebody expicitly says "release". Do we want e.g. the perf tests to run on a debug build?

[vtjnash]

good catch, i wanted to express "debug & !release". so, maybe it should be:

JULIA_DEBUG = 0
ifeq (,$(findstring release,$(MAKECMDGOALS)))
ifneq (,$(findstring debug,$(MAKECMDGOALS)))
JULIA_DEBUG = 1
endif
endif

[vtjnash]

merged as a4d019e

i decided to go ahead and make the tweaks i was suggesting as a followup commit. now make debug test does the "right thing"

[tkelman]

would've been ideal to do that in a pr first, given the appveyor breakage