%pyproject_install: pass %{_prefix} explicitly to pip install

This makes things work for %{_prefix} other than user, when combined
with a change in python-rpm-macros to the definition of python3_sitelib/python3_sitearch.

https://lists.fedoraproject.org/archives/list/python-devel@lists.fedoraproject.org/thread/KEQMMNJ4HTTHSQLK6P4DJJTVPA36SS3W/

Related: rhbz#2117571

Co-Authored-By: Miro Hrončok <miro@hroncok.cz>

macros.pyproject

@@ -54,7 +54,7 @@ echo $(IFS=:; echo "${pyproject_build_lib[*]}")
 
 %pyproject_install() %{expand:\\\
 specifier=$(ls %{_pyproject_wheeldir}/*.whl | xargs basename --multiple | sed -E 's/([^-]+)-([^-]+)-.+\\\.whl/\\\1==\\\2/')
-TMPDIR="%{_pyproject_builddir}" %{__python3} -m pip install --root %{buildroot} --no-deps --disable-pip-version-check --progress-bar off --verbose --ignore-installed --no-warn-script-location --no-index --no-cache-dir --find-links %{_pyproject_wheeldir} $specifier
+TMPDIR="%{_pyproject_builddir}" %{__python3} -m pip install --root %{buildroot} --prefix %{_prefix} --no-deps --disable-pip-version-check --progress-bar off --verbose --ignore-installed --no-warn-script-location --no-index --no-cache-dir --find-links %{_pyproject_wheeldir} $specifier
 if [ -d %{buildroot}%{_bindir} ]; then
   %py3_shebang_fix %{buildroot}%{_bindir}/*
   rm -rfv %{buildroot}%{_bindir}/__pycache__

pyproject-rpm-macros.spec

@@ -12,7 +12,7 @@ License:        MIT
 #   Increment Y and reset Z when new macros or features are added
 #   Increment Z when this is a bugfix or a cosmetic change
 # Dropping support for EOL Fedoras is *not* considered a breaking change
-Version:        1.3.0
+Version:        1.3.1
 Release:        1%{?dist}
 
 # Macro files
@@ -126,6 +126,9 @@ export HOSTNAME="rpmbuild"  # to speedup tox in network-less mock, see rhbz#1856
 %license LICENSE
 
 %changelog
+* Tue Jun 27 2022 Owen Taylor <otaylor@redhat.com> - 1.3.1-1
+- %%pyproject_install: pass %%{_prefix} explicitly to pip install
+
 * Thu May 12 2022 Miro Hrončok <mhroncok@redhat.com> - 1.3.0-1
 - Use tomllib from the standard library on Python 3.11+
 

tests/tldr.spec

@@ -11,12 +11,19 @@ BuildArch:      noarch
 BuildRequires:  python3-devel
 BuildRequires:  pyproject-rpm-macros
 
+%if 0%{?fedora} >= 36 || 0%{?rhel} >= 10
+# Internal check for our macros: test that we can install to a custom prefix
+BuildRequires:  python3-rpm-macros >= 3.10-18
+%global _prefix /app
+%endif
+
 %description
 A Python package containing executables.
 Building this tests:
 - there are no bytecompiled files in %%{_bindir}
 - the executable's shebang is adjusted properly
 - file direct_url.json isn't created
+- installation to custom prefix works
 
 %prep
 %autosetup -n %{name}-%{version}
@@ -48,6 +55,12 @@ test "%{pyproject_build_lib}" == "${PWD}/build/lib"
 test "%{pyproject_build_lib}" == "$(echo %{_pyproject_builddir}/pip-req-build-*/build/lib)"
 %endif
 
+%if 0%{?fedora} >= 36 || 0%{?rhel} >= 10
+# Internal check for custom prefix
+grep '^/usr' %{pyproject_files} && exit 1 || true
+grep '^/app' %{pyproject_files}
+%endif
+
 %files -f %pyproject_files
 %license LICENSE
 %doc README.md