[Buildroot] Advice needed: Problem with clashing make variables in pkg-generic.mk when building perl-xml-sax package.

[Yann E. MORIN <yann.morin.1998@free.fr>]

Joeri, Arnout, All,

On 2017-10-23 23:05 +0200, Arnout Vandecappelle spake thusly:
> On 23-10-17 16:41, Barbarien, Joeri (Nokia - BE/Antwerp) wrote:
> > Hello all,
> > 
> > When building perl-xml-sax (and its dependency perl-xml-sax-base) I noticed something strange in output/build/packages-file-list.txt:
> [snip]
> > The files that are listed for perl-xml-sax-0.99 are actually those built by perl-xml-sax-base
> > 
> > This is due to a clash of make variables in package/pkg-generic.mk:
> > 
> > $(2)_BASE_NAME  = $$(if $$($(2)_VERSION),$(1)-$$($(2)_VERSION),$(1))
> > $(2)_RAW_BASE_NAME = $$(if $$($(2)_VERSION),$$($(2)_RAWNAME)-$$($(2)_VERSION),$$($(2)_RAWNAME))
> > $(2)_DL_DIR =  $$(DL_DIR)
> > $(2)_DIR  =  $$(BUILD_DIR)/$$($(2)_BASE_NAME)
> > 
> > Due to the unfortunate naming of the packages,
> > 
> > $($(2)_BASE_NAME) for perl-xml-sax clashes with as $($(2)_NAME) for perl-xml-sax-base, leading to this wrong behavior.
> 
>  Wow, good catch! Incredible that this works at all...

Yes, this is a very good catch... Damned... :-/

I am basically in line with the analysis by Arnout: any solution we
decide on will be a huge work.

I think we really need to sleep on it for a little while, because we
definitely must be very cafreful that a solution:

  - does not introduces regressions

  - can be applied in as systematice a way as possible

  - does not need a second round to fix a fallout.

I think I will wait coming back from ELCE before I have a deep look at
this, though.

Notice that we have a similar problem for host packages: a target package
that is named foo and has a host variant could be confused with a target
package that is named host-foo, and then we'd have a clash in the
variable names as well...

Regards,
Yann E. MORIN.

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