[mini] Explicitly turn nunit output on or off based on variable

[akoeplinger]

Alternative implementation to 8f09214.

In CI we explicitly pass EMIT_NUNIT=1 to generate the nunit xml and run the check-seq-points tests, locally those are omitted. This avoids needing to sniff for Jenkins/Wrench variables.

@vargaz what do you think?

[vargaz]

Does wrench pass this ?
It would be better if jenkins would pass CI=1 as well.

[akoeplinger]

@vargaz we can change Wrench to pass it, but it does nothing with NUnit anyway. As I said, I'd prefer making it explicit when something happens differently on CI, instead of the Makefile somehow detecting it's run on CI.

[vargaz]

Its ok.

[vargaz]

It would better to do the detection in make imho instead of passing an if-then-else to the shell.

[akoeplinger]

I tried this first, but since it is an automake file I can't use the normal ifeq checks I'd do in make, so this seemed like the easiest solution to me. If you know how to fight the automake dragon, please show me 😄

[vargaz]

Thats what the original change did, we computed a target name and made rcheck depend on it.

[akoeplinger]

@vargaz fixed. I just found the shell solution a bit clearer, but I don't care much about that.

[vargaz]

Looks ok.