Re: should an empty "pkgdata_DATA" cause creation of $(pkgdatadir) by "make install"? (was: Re: [PATCH] gnulib-tool: fix imprecise comments)

[Bruno Haible]

[Dropping bug-gnulib from CC.]

Stefano Lattarini wrote:
> So we're in a sort of a tie here: some users think that the current Automake
> behaviour is a feature (and I lean toward that position), other ones (with
> Ralf among them, apparently) believe it's a bug.  Hmmm.

The most important question in such a situation is: Can users who wish to
have the opposite behaviour get it?

If the answer to this question is yes, then: What are the use-cases of these
two behaviours? Are they sound? How many users do they affect?

About the first question:

  * If Automake does not create an empty directory by default, can users
    get it created?

    Answer: Yes, they write a rule like this:

        installdirs-local:
                $(mkdir_p) $(DESTDIR)$(pkgdatadir)

  * If Automake does create an empty directory by default, can users avoid
    it?

    Answer: For users who generate their Makefile.am (like gnulib-tool), yes.
    For users who use constructs like

        pkgdata_DATA =
        if WINDOWS
        pkgdata_DATA += documentation.chm
        endif
        if MACOS
        pkgdata_DATA += bundle.nib
        endif

    what is the answer? Can they write

        if WINDOWS || MACOS
        pkgdata_DATA =
        if WINDOWS
        pkgdata_DATA += documentation.chm
        endif
        if MACOS
        pkgdata_DATA += bundle.nib
        endif
        endif

    Does this have the effect of avoiding an empty directory?

Second question:

  * Who needs to avoid an empty installation directory?

    I think, everyone who installs files conditionally. Can be many packages.

  * Who needs to create an empty installation directory?

    Hmm?

Please fill in the remaining answers; I could only come up with partial
answers.

Bruno