[#3732] Switch meson.sh from venv to pyinstall to avoid venv depdendency when packaging

meson.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -eu
+
 # Pulls the latest meson that has fix https://github.com/mesonbuild/meson/pull/13532
 # for issue https://github.com/mesonbuild/meson/issues/11322.
 #
@@ -19,35 +21,59 @@ lt() {
     return 0
 }
 
-if test ! -d venv; then
-    # Starting with Meson 0.62, Python 3.7 is required.
-    python3=python3
-    v=$(python3 -c 'import platform; print(platform.python_version())')
-    if lt "${v}" 3.7.0; then
-        # Search for a newer Python.
-        if command -V compgen >/dev/null; then
-            # shellcheck disable=SC3044
-            # SC3044 (warning): In POSIX sh, 'compgen' is undefined.
-            newer=$(compgen -c python3 | grep -E '^python3.[0-9]+$' | sort -V | tail -n 1)
-            if test -n "${newer}"; then
-                python3="${newer}"
+# Change directory to Kea's top level directory.
+top_level=$(cd "$(dirname "${0}")" && pwd)
+cd "${top_level}" || exit 1
+
+if command -v meson > /dev/null 2>&1 && lt 1.7.98 "$(meson --version)"; then
+    # Good to be used. Does not suffer from endless transitional dependency iteration.
+    meson='meson'
+else
+    meson='./.meson/meson'
+    if test ! -f "${meson}"; then
+        # Starting with Meson 0.62, Python 3.7 is required.
+        python3=python3
+        v=$(python3 -c 'import platform; print(platform.python_version())')
+        if lt "${v}" 3.7.0; then
+            # Search for a newer Python.
+            if command -V compgen >/dev/null; then
+                # shellcheck disable=SC3044
+                # SC3044 (warning): In POSIX sh, 'compgen' is undefined.
+                newer=$(compgen -c python3 | grep -E '^python3.[0-9]+$' | sort -V | tail -n 1)
+                if test -n "${newer}"; then
+                    python3="${newer}"
+                fi
             fi
         fi
+
+        v=$("${python3}" -c 'import platform; print(platform.python_version())')
+        printf 'Python version: %s\n' "${v}"
+
+        git clone https://github.com/mesonbuild/meson .meson-src
+        (
+            cd .meson-src || exit 1
+            if git tag -l | grep -E '^1.8.0$' > /dev/null 2>&1; then
+                git checkout 1.8.0
+            fi
+        )
+
+        "${python3}" -m venv ./.venv
+        ./.venv/bin/pip install --upgrade pip
+
+        ./.venv/bin/pip install ninja
+        ./.venv/bin/pip install pyinstaller
+        (
+            cd .meson-src || exit 1
+            "${top_level}/.venv/bin/pyinstaller" --additional-hooks-dir=packaging --clean --dist "${top_level}/.meson" --onefile ./meson.py
+        )
+        cp ./.venv/bin/ninja ./.meson/ninja
+        rm -fr ./.meson-src ./.venv
     fi
-
-    v=$("${python3}" -c 'import platform; print(platform.python_version())')
-    printf 'Python version: %s\n' "${v}"
-
-    "${python3}" -m venv ./venv
-    ./venv/bin/pip install --upgrade pip
-
-    # When meson 1.8 will be released, we can pin the versions.
-    ./venv/bin/pip install git+https://github.com/mesonbuild/meson.git
-    ./venv/bin/pip install ninja
 fi
 
-# shellcheck disable=SC1091
-# SC1091: Not following: ... was not specified as input (see shellcheck -x).
-. ./venv/bin/activate
+if test -f "${top_level}/.meson/ninja"; then
+    # To find ninja in case it went with the pyinstalled version.
+    export PATH="${top_level}/.meson:${PATH}"
+fi
 
-meson "${@}"
+"${meson}" "${@}"