[pacman-dev] makepkg enhancements: globstar and variable expansions in PURGE_TARGETS, MAN_DIRS, etc.

[Ciprian Dorin, Craciun]

    Hy everybody!

    While building some custom packages for a stripped down Linux
server, I've hit the following problems:
    * the cause of the problems is from the pact that my packages are
each in it's own folder like: /packages/bash--4.0--1,
/packages/busybox--1.15.2--1, etc., and thus,
    * MAN_DIRS, DOC_DIRS, STRIP_DIRS and PRUNE_TARGETS doesn't work,
as I have no way to use ${pkgname}, etc in there;
    * in PRUNE_TARGETS there is no way to specify file patterns (like
'*.a', or '*.la'), but only from certain folders; (for example I can
say '*.a', but not '../lib/*.a'; also I can not specify unknown number
of parents, like '.../lib/**/*.a';

    As a consequence, I propose (and if accepted I also have the
patches for) the following enhancements:
    * allow the patterns in MAN_DIRS, etc. to be evaluated at the
proper time execution time (when we access MAN_DIRS), not at
configuration time (when we define MAN_DIRS); this can be achieved by
(single) quoting the patterns like:
'package/${pkgname}--${pkgver}--${pkgrel}/{,share/}man' and then
expansion by using eval;
    * allow enhanced pattern types for PURGE_TARGETS, like:
        * the same lazy evaluation as above;
        * if a pattern starts with '=' then it must exactly match a file name;
        * if a pattern starts with '+' then it is a glob pattern (or
globstar), like:
'packages/${pkgname}--${pkgver}--${pkgrel}/lib/**/*.a'
        * if a pattern ends with '/' then we use `rm -Rf`, else we use `rm -f`
        * maybe if a pattern starts with '@' then it is a regular
expression, etc. (this I have not implemented);

    Any comments?

    Also one more question: just before packaging we remove the pkg
folder. Shouldn't we also do the same with src when rebuilding a
package? (We are re-extracting the contents of archives, but some
packages leave garbage behind when building, and this garbage could
interfere with a new build...)

    Thanks,
    Ciprian.