I may have missed it, but I did not see where there was something making sure qmake was included before qt.

Would a match ala

.if empty(USES:Mqt.*qmake) 
IGNORE=qmake must appear before qt in USES
.endif

work?

That should not be needed, qmake_ARGS should always be defined, unless this is because we can come here from USES=qt-dist.

No, it has to work whatever the order they are added. You'll have to include qt.mk after ading to USE_QT.

I see that qt.mk is already included early here, so adding to USE_QT doesn't, does it? Or maybe it is handled in POST so it does work.

At this point, PORTSDIR should always be defined.

You know

tar_ARGS=        xz
​.include "${USESDIR}/tar.mk"

could be written as:

EXTRACT_SUFX?=  .tar.xz

And it would probably be faster, one less file to open and parse.

You could probably write USE_QT=${USE_QT4} / USE_QT=${USE_QT5} to help a bit more.

I think I added the POST stuff because of this, but I have to check whether it works in any order already.

Please do test, it works whatever the order USES is set. (There is a sort police that likes to have it sorted, but the order is really undefined.)

 #  make -VUSES -VUSE_QT -Cdevel/qbs
compiler:c++11-lib python:run qt:5 qmake:outsource shebangfix
buildtools_build core concurrent gui network script testlib  widgets xml qmake_build

seems to work \o/

I think qt-dist should do a qt_ARGS?= so that qt is not special like that in any way

The only reason we use .CURDIR:H:H in ports to reference PORTSDIR is because bsd.port.mk has not yet been included, and PORTSDIR is not yet defined. Here, we are in a USES, and PORTSDIR is always defined, it should be used instead of the obscure .CURDIR:H:H.

This should probably be in the SANITY_UNSUPORTED, not here. The ALL_* variables are for user facing variables, stuff you put in make.conf, for example. I don't think QT_NONSTANDARD is in that category.

woops, stray empty line...