Re: AC_SUBST'ing foodir correctly?

[Nick Bowler]

On 2016-05-24, Wouter Verhelst <address@hidden> wrote:
> I'm adding a systemd unit to my package. To that end, I'm checking if
> there is a pkg-config .pc file for systemd which sets a variable
> "systemdsystemunitdir", and am trying to install the systemd unit in
> that location.
[snip configure script computes systemdunitdir from pkg-config]
> and then in my Makefile.am:
>
> if SYSTEMD
> systemdunit_DATA = address@hidden
> endif
>
> (if you need the full files, they're in the git repository at
> git.debian.org/users/wouter/nbd.git)
>
> However, now my "make distcheck" fails, because the "make install"
> target disregards DESTDIR and tries to install files in the actual
> systemd unit directory, rather than the staging one. Clearly this means
> I'm doing something wrong, but I'm not sure what the proper way for
> doing this would be.

I suspect it is not the DESTDIR check which is failing -- the problem
is that your installation directory ignores prefix.  The package must
install all files into ${prefix}-relative locations by default.

Basically, distcheck is telling you that unprivileged installs will
fail because they try to install to /usr somewhere.

Here are some basic options, in increasing order of complexity:

  - Don't install the unit files (user can copy them manually).

  - Don't autodetect at all: just default to some ${prefix}-relative
    installation directory and allow the user to change it manually.
    E.g., make systemdunitdir=/path/to/wherever.

  - Munge the autodetected path into something relative to ${prefix}.

See "Installing to Hard-Coded Locations"[1] in the Automake manual for
some more information on this topic.

[1] 
https://www.gnu.org/software/automake/manual/automake.html#Hard_002dCoded-Install-Paths

Cheers,
  Nick