+++ This bug was initially created as a clone of Bug #1028953 +++

Current state:
Intra- and inter- collection dependency macros are currently not consistent and the intercollection dependency macro isn't very useful. Consider this case:
Collection A has package "a", collection B has package "b" and "c". "c" requires "b" and "a". Currently, "c" specfile has this:

Requires: %{?scl_prefix}b
Requires: %{?scl:%scl_require_package A a}%{!?scl:a}

The first require (intrascl dep) is fine but the second one (interscl dep) is very inconvenient. I'd like to propose modification of %scl_prefix macro to something like this (maybe it can be written in a nicer way, but it works this way):

%scl_prefix() %(if [ "%1" = "%%1" ]; then echo "%{scl}-"; else echo "%1-"; fi)

In short, this makes %scl_prefix a macro function, which uses optional argument as the scl name, and defaults to %scl if no argument is provided. With this, we would be able to use it like this:

Requires: %{?scl_prefix}b
Requires: %{?scl:%scl_prefix A}a

The second Require is now more convenient and comprehensible.

--- Additional comment from Jan Zeleny on 2013-11-15 06:36:25 EST ---

How about the final result being something like

Requires: %{scl_requires_package mysql55 mysql}

It works well regardless if it's built for scl or not, I have just tried. Would this be acceptable for you? (note that I changed the name to keep the backwards compatibility of the original macros)

--- Additional comment from Bohuslav "Slavek" Kabrda on 2013-11-15 06:54:53 EST ---

(In reply to Jan Zeleny from comment #1)
> How about the final result being something like
> 
> Requires: %{scl_requires_package mysql55 mysql}
> 
> It works well regardless if it's built for scl or not, I have just tried.
> Would this be acceptable for you? (note that I changed the name to keep the
> backwards compatibility of the original macros)

No, because I still have to use the %{!?scl:a} part in

Requires: %{?scl:%scl_require_package A a}%{!?scl:a}

if I want to build the package in a buildroot without scl-utils-build.

Also, would this cover this use case?


%global mysql_collection mysql55
Requires: %{?scl:%scl_prefix %{?mysql_collection}}mysql # => mysql55-mysql

# now delete definition of mysql_collection macro
Requires: %{?scl:%scl_prefix %{?mysql_collection}}mysql # <current_scl>-mysql


My implementation does.

--- Additional comment from Jan Zeleny on 2013-11-15 09:56:25 EST ---

Ok, thanks for the information. I was just playing here with a few possibilities so I wanted to better understand your use case.