%build -a and %install -a overwrite build/installation instructions from %buildsystem_*_*

[berolinux]

Describe the bug
I've just updated my rpm to 4.19.90, and tried out the declarative build bits. Overall, they're working nicely, but %build -a doesn't seem to work as documented - instead of adding to %buildsystem_*_build, it is treated as the only build/install script present.

To Reproduce
Steps to reproduce the behavior:
Simplified version of the macros I've been playing with (simplified to not call any other macros etc. for easier reproducibility etc.):

%buildsystem_autotools_conf() \
    ./configure --prefix=/usr %*
%buildsystem_autotools_build() \
    make %*
%buildsystem_autotools_install() \
    make install %*

Everything works as expected if I don't have any %build section in the spec - but if I add

%build -a
echo test

in the spec, only echo test is executed, not make.

Expected behavior
The code is built (make), and afterwards test is printed.

Output
test is printed, without any signs of running make.

Environment

• OS / Distribution: OpenMandriva Cooker
• Version rpm-4.19.90

Additional context
There's no funky stuff like macros redefining %build or something (that actually used to be present in older Mandriva versions).

$ rpmbuild --eval '%{build}'
%{build}

Simplified spec that works:

Summary:        A utility for determining file types
Name:           file
Version:        5.45
Release:        1
License:        BSD
Url:            https://www.darwinsys.com/file/
Source0:        ftp://ftp.astron.com/pub/file/%{name}-%{version}.tar.gz
BuildSystem: autotools
BuildOption: --enable-static

%description
A utility for determining file types

%files
/usr

Modified version of the spec that shows the problem:

Summary:        A utility for determining file types
Name:           file
Version:        5.45
Release:        1
License:        BSD
Url:            https://www.darwinsys.com/file/
Source0:        ftp://ftp.astron.com/pub/file/%{name}-%{version}.tar.gz
BuildSystem: autotools
BuildOption: --enable-static

%description
A utility for determining file types

%build -a
echo test

%install -a
echo test

%files
/usr

[pmatilai]

Hmm, ugh. We have a test for this very scenario (%build -a) in the test-suite, but looking closer indeed the buildsystem %build is lost. It's just that autotools "make install" masks the issue by building automatically since not already done. We also have bunch of other tests for -a/-p modes, so this is just a bad interaction between the buildsystem stuff and append/prepend. Which does mean the buildsystem thing is rather broken in the alpha then 😒

Thanks for the report!

Another buildsystem related breakage spotted while looking at this is that on Fedora there's this old hack around %install which breaks with -a and -p:

%install %{?_enable_debug_packages:%{?buildsubdir:%{debug_package}}}\
%%install\
%{nil}

It's going to need an expedited fix for #2204