diff --git a/.cirrus.yml b/.cirrus.yml
index 8da695c4dd8b1..75801105f82b0 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -138,6 +138,7 @@ task:
     TEST_JOBS: 3
 
     CCACHE_DIR: /tmp/ccache_dir
+    INSTALL_DIR: /tmp/meson-install
     CPPFLAGS: -DRELCACHE_FORCE_RELEASE -DCOPY_PARSE_PLAN_TREES -DWRITE_READ_PARSE_PLAN_TREES -DRAW_EXPRESSION_COVERAGE_TEST
     CFLAGS: -Og -ggdb
 
@@ -187,6 +188,7 @@ task:
         build
     EOF
   build_script: su postgres -c 'ninja -C build -j${BUILD_JOBS}'
+  install_script: su postgres -c 'ninja -C build install'
   upload_caches: ccache
 
   test_world_script: |
@@ -201,13 +203,13 @@ task:
       set -e
       ulimit -c unlimited
       meson test $MTEST_ARGS --quiet --suite setup
-      export LD_LIBRARY_PATH="$(pwd)/build/tmp_install/usr/local/pgsql/lib/:$LD_LIBRARY_PATH"
+      export LD_LIBRARY_PATH="${INSTALL_DIR}/lib/:$LD_LIBRARY_PATH"
       mkdir -p build/testrun
-      build/tmp_install/usr/local/pgsql/bin/initdb -N build/runningcheck --no-instructions -A trust
+      ${INSTALL_DIR}/bin/initdb -N build/runningcheck --no-instructions -A trust
       echo "include '$(pwd)/src/tools/ci/pg_ci_base.conf'" >> build/runningcheck/postgresql.conf
-      build/tmp_install/usr/local/pgsql/bin/pg_ctl -c -o '-c fsync=off' -D build/runningcheck -l build/testrun/runningcheck.log start
+      ${INSTALL_DIR}/bin/pg_ctl -c -o '-c fsync=off' -D build/runningcheck -l build/testrun/runningcheck.log start
       meson test $MTEST_ARGS --num-processes ${TEST_JOBS} --setup running
-      build/tmp_install/usr/local/pgsql/bin/pg_ctl -D build/runningcheck stop
+      ${INSTALL_DIR}/bin/pg_ctl -D build/runningcheck stop
     EOF
 
   on_failure:
@@ -231,6 +233,7 @@ task:
 
     CIRRUS_WORKING_DIR: /home/postgres/postgres
     CCACHE_DIR: /tmp/ccache_dir
+    INSTALL_DIR: /tmp/meson-install
 
     PATH: /usr/sbin:$PATH
 
@@ -288,6 +291,7 @@ task:
     su postgres <<-EOF
       meson setup \
         --buildtype debug \
+        --prefix=${INSTALL_DIR} \
         -Dcassert=true -Dssl=openssl ${UUID} \
         -DPG_TEST_EXTRA="$PG_TEST_EXTRA" \
         ${INCLUDE_DIRS} \
@@ -295,6 +299,7 @@ task:
     EOF
 
   build_script: su postgres -c 'ninja -C build -j${BUILD_JOBS}'
+  install_script: su postgres -c 'ninja -C build install'
   upload_caches: ccache
 
   test_world_script: |
@@ -355,6 +360,7 @@ task:
     TEST_JOBS: 8 # experimentally derived to be a decent choice
 
     CCACHE_DIR: /tmp/ccache_dir
+    INSTALL_DIR: /tmp/meson-install
     DEBUGINFOD_URLS: "https://debuginfod.debian.net"
 
     # Enable a reasonable set of sanitizers. Use the linux task for that, as
@@ -462,6 +468,7 @@ task:
         su postgres <<-EOF
           meson setup \
             --buildtype=debug \
+            --prefix=${INSTALL_DIR} \
             -Dcassert=true \
             ${LINUX_MESON_FEATURES} \
             -DPG_TEST_EXTRA="$PG_TEST_EXTRA" \
@@ -475,6 +482,7 @@ task:
           export CC='ccache gcc -m32'
           meson setup \
             --buildtype=debug \
+            --prefix=${INSTALL_DIR}-32 \
             -Dcassert=true \
             ${LINUX_MESON_FEATURES} \
             -Dllvm=disabled \
@@ -486,6 +494,7 @@ task:
 
       build_script: su postgres -c 'ninja -C build -j${BUILD_JOBS}'
       build_32_script: su postgres -c 'ninja -C build-32 -j${BUILD_JOBS}'
+      install_script: su postgres -c 'ninja -C build install'
 
       upload_caches: ccache
 
@@ -497,6 +506,8 @@ task:
         # so that we don't upload 64bit logs if 32bit fails
         rm -rf build/
 
+      install_32_script: su postgres -c 'ninja -C build-32 install'
+
       # There's currently no coverage of icu with LANG=C in the buildfarm. We
       # can easily provide some here by running one of the sets of tests that
       # way. Newer versions of python insist on changing the LC_CTYPE away
@@ -521,6 +532,7 @@ task:
     TEST_JOBS: 8 # experimentally derived to be a decent choice
 
     CCACHE_DIR: /tmp/ccache_dir
+    INSTALL_DIR: /tmp/meson-install
     DEBUGINFOD_URLS: ${DEBUGINFO}
 
     TCL_DIR: /usr/lib64/
@@ -572,12 +584,14 @@ task:
     su postgres <<-EOF
       meson setup \
         --buildtype debug \
+        --prefix=${INSTALL_DIR} \
         -Dcassert=true -Dssl=openssl -Duuid=e2fs ${LLVM} \
         -DPG_TEST_EXTRA="$PG_TEST_EXTRA" \
         build
     EOF
 
   build_script: su postgres -c 'ninja -C build -j${BUILD_JOBS}'
+  install_script: su postgres -c 'ninja -C build install'
   upload_caches: ccache
 
   test_world_script: |
@@ -603,6 +617,7 @@ task:
 
     CIRRUS_WORKING_DIR: ${HOME}/pgsql/
     CCACHE_DIR: ${HOME}/ccache
+    INSTALL_DIR: /tmp/meson-install
     HOMEBREW_CACHE: ${HOME}/homebrew-cache
     PERL5LIB: ${HOME}/perl5/lib/perl5
 
@@ -675,6 +690,8 @@ task:
 
     meson setup \
       --buildtype=debug \
+      --prefix=${INSTALL_DIR} \
+      -Dpkg_config_path=$PKG_CONFIG_PATH \
       -Dextra_include_dirs=${brewpath}/include \
       -Dextra_lib_dirs=${brewpath}/lib \
       -Dcassert=true \
@@ -684,6 +701,7 @@ task:
       build
 
   build_script: ninja -C build -j${BUILD_JOBS}
+  install_script: ninja -C build install
   upload_caches: ccache
 
   test_world_script: |
diff --git a/meson.build b/meson.build
index 8aa44d2350c44..bac3dec0ee6cb 100644
--- a/meson.build
+++ b/meson.build
@@ -3102,6 +3102,26 @@ test('install_test_files',
 
 test_result_dir = meson.build_root() / 'testrun'
 
+# it seems freebsd doesn't use libdir for pkgconfig path
+if host_system == 'freebsd'
+  pkgconf_installdir =  dir_prefix / 'libdata' / 'pkgconfig'
+else
+  pkgconf_installdir = dir_prefix / dir_lib / 'pkgconfig'
+endif
+test_pkg_conf_file = files('src/tools/ci/test_pkg_conf')
+test('pkg_conf_extensions',
+    test_pkg_conf_file,
+    args: [
+      '--meson', meson_bin.path(),
+      '--meson_args', meson_args,
+      '--rootdir', meson.source_root(),
+      '--pkgconf_installdir', pkgconf_installdir,
+      '--builddir', meson.build_root(),
+      '--pkg_conf_path', get_option('pkg_config_path'),
+      '--',
+        cc.cmd_array(),
+      ],)
+
 
 # XXX: pg_regress doesn't assign unique ports on windows. To avoid the
 # inevitable conflicts from running tests in parallel, hackishly assign
diff --git a/src/tools/ci/test_pkg_conf b/src/tools/ci/test_pkg_conf
new file mode 100644
index 0000000000000..fe7febaff0a6f
--- /dev/null
+++ b/src/tools/ci/test_pkg_conf
@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+
+import argparse
+import ast
+import shutil
+import subprocess
+import os
+import sys
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('--rootdir', help='root directory',
+                    type=str, required=True)
+parser.add_argument('--pkgconf_installdir', help='pkgconf install directory',
+                    type=str, required=True)
+parser.add_argument('--builddir', help='build directory',
+                    type=str, required=True)
+parser.add_argument('--meson', help='path to meson binary',
+                    type=str, required=True)
+parser.add_argument('--meson_args', help='args of meson binary',
+                    type=str, nargs='*', required=False)
+parser.add_argument('--pkg_conf_path',
+                    help='PKG_CONF_PATH from surrounding meson build',
+                    type=str, nargs='?', const='', required=False)
+
+parser.add_argument('c_args', help='c_args from surrounding meson build',
+                     nargs='*')
+
+args = parser.parse_args()
+
+rootdir = os.path.realpath(args.rootdir)
+builddir = os.path.realpath(args.builddir)
+pkgconf_installdir = os.path.realpath(args.pkgconf_installdir)
+adminpackdir = os.path.join(rootdir, 'contrib/adminpack/')
+workdir = os.path.join(builddir, 'contrib/adminpack_tmp')
+meson_args = ' '.join(args.meson_args)
+c_args = ' '.join(args.c_args)
+exit_code = 0
+
+adminpack_meson_build_file = \
+  '''
+  project('adminpack', 'c')
+
+  pg_ext = dependency('postgresql-extension-warnings')
+
+  adminpack = shared_module('adminpack',
+    ['{}adminpack.c'],
+    dependencies: pg_ext,
+    name_prefix: '',
+    install_dir: pg_ext.get_variable(pkgconfig: 'dir_mod')
+  )
+
+  install_data(
+    '{}adminpack.control',
+    '{}adminpack--1.0.sql',
+    '{}adminpack--1.0--1.1.sql',
+    '{}adminpack--1.1--2.0.sql',
+    '{}adminpack--2.0--2.1.sql',
+    install_dir: pg_ext.get_variable(pkgconfig: 'dir_data')
+  )
+  '''.format(adminpackdir, adminpackdir, adminpackdir, adminpackdir,
+             adminpackdir, adminpackdir)
+
+# clear workdir
+if os.path.exists(workdir):
+    shutil.rmtree(workdir)
+os.makedirs(workdir)
+
+# overwrite meson.build file
+meson_file = os.path.join(workdir, 'meson.build')
+with open(meson_file, 'w') as f:
+    f.write(adminpack_meson_build_file)
+
+
+def remove_duplicates(duplicate_str):
+  words = duplicate_str.split()
+  return ' '.join(sorted(set(words), key=words.index))
+
+
+# run tests
+def run_tests(pkg_conf_path, message=''):
+    print('\n{}\n{}\n'.format('#' * 60, message), flush=True)
+
+    adminpack_builddir = os.path.join(workdir, 'build')
+
+    env = {**os.environ, }
+    env['PKG_CONFIG_PATH'] = '{}:{}:{}'.format(
+      pkg_conf_path, args.pkg_conf_path, env.get('PKG_CONFIG_PATH', ''),
+    ).strip(': ')
+    env['CC'] = '{} {}'.format(
+      c_args, env.get('CC', ''),
+    )
+    env['CC'] = remove_duplicates(env['CC'])
+
+    if os.path.exists(adminpack_builddir):
+        shutil.rmtree(adminpack_builddir)
+
+    if meson_args:
+      meson_setup_command = [args.meson, meson_args, 'setup', 'build']
+    else:
+      meson_setup_command = [args.meson, 'setup', 'build']
+
+    ninja_build_command = ['ninja', '-C', 'build', '-v']
+    if subprocess.run(meson_setup_command, env=env,
+                      cwd=workdir).returncode != 0:
+        return False
+    if subprocess.run(ninja_build_command, cwd=workdir).returncode != 0:
+        return False
+    return True
+
+
+# test postgresql-extension-warnings
+if not run_tests(pkgconf_installdir,
+          message='Testing postgresql-extension-warnings'):
+  exit_code = exit_code + 1
+
+
+# test postgresql-extension-warnings-uninstalled
+if not run_tests(os.path.join(builddir, 'meson-uninstalled'),
+          message='Testing postgresql-extension-warnings-uninstalled'):
+  exit_code = exit_code + 1
+
+sys.exit(exit_code)