[zxwrt]

The wrong part in GNU make is that it always permit using non-posix extensions regardless of .POSIX special target, while pdpmake does not. This fact makes pdpmake kinda special since it can be used for posix compliance testing, which is crucial part of developing portable application that uses make to build itself.

[hvdijk]

That's not wrong. It's something that not everybody will like, but as long as the extensions don't conflict with anything specified by POSIX, that is permitted.

To me, the decision to let POSIX mode turn off extensions that are so widely available in other implementations that they have been approved for the next version of POSIX is an odd one. There is little reason not to already use those features today: using them is not going to seriously limit your portability. If you use them, you cannot also use pdpmake's POSIX mode. The obvious conclusion there, to me, is not to avoid using those features, but to avoid using pdpmake's POSIX mode.

[zxwrt]

I agree that disabling will-be-posix extensions in POSIX mode sounds like an extreme idea, but seriously, such strictness is the main point of the pdpmake. It ensures that implementation conform to the current standard, not draft which may change quite often.

[hvdijk]

It turns out it's actually pdpmake-build-time-configurable. If you build with -DENABLE_FEATURE_MAKE_EXTENSIONS -DENABLE_FEATURE_MAKE_POSIX_202X, extensions are enabled by default, and .POSIX only flags non-POSIX-202x extensions. I don't know what, if anything, this says about the main point of pdpmake, but I'm glad with this mode.