fix: say why Flatpak setup failed instead of blaming the mirrors (#1580)

tools/linuxfs/overlay/usr/local/bin/droiddeck-flatpak-setup

@@ -3,6 +3,7 @@ set -u
 export LANG=C.UTF-8
 step() { echo "== STEP $*"; }
 fail() { echo "== FAIL $*"; exit 1; }
+[ "$(id -u)" = 0 ] || fail "needs root: install Flatpak from the launcher's Store, which runs this as root"
 
 PACKAGES="flatpak ostree appstream libxmlb libmalcontent libfyaml accountsservice composefs xdg-dbus-proxy"
 while read -r pkg probe; do
@@ -48,10 +49,13 @@ if [ ! -f /etc/pacman.d/gnupg/pubring.gpg ] && [ ! -f /etc/pacman.d/gnupg/pubrin
 fi
 
 step "Reading the package lists"
-pacman --config "$CONF" --dbpath "$WORK/db" --noconfirm -Sy >/dev/null 2>&1 \
-  || pacman --config "$CONF" --dbpath "$WORK/db" --noconfirm -Sy 2>&1 | tail -3 \
-  || fail "could not reach the Arch Linux ARM mirrors"
-[ -f "$WORK/db/sync/extra.db" ] || fail "could not reach the Arch Linux ARM mirrors"
+sync_log=$(pacman --config "$CONF" --dbpath "$WORK/db" --noconfirm -Sy 2>&1) \
+  || sync_log=$(pacman --config "$CONF" --dbpath "$WORK/db" --noconfirm -Sy 2>&1)
+if [ ! -f "$WORK/db/sync/extra.db" ]; then
+  printf '%s\n' "$sync_log" | tail -3
+  reason=$(printf '%s\n' "$sync_log" | grep -m1 -i '^error' | cut -c1-160)
+  fail "could not reach the Arch Linux ARM mirrors${reason:+ ($reason)}"
+fi
 
 step "Downloading Flatpak"
 out=$(pacman --config "$CONF" --dbpath "$WORK/db" --cachedir "$WORK/pkg" --noconfirm -Sw -dd $PACKAGES 2>&1)

tools/tests/test_flatpak_setup.py

@@ -0,0 +1,45 @@
+import os
+from pathlib import Path
+import subprocess
+import tempfile
+import unittest
+
+
+SCRIPT = Path(__file__).resolve().parents[1] / "linuxfs/overlay/usr/local/bin/droiddeck-flatpak-setup"
+
+
+class FlatpakSetupTest(unittest.TestCase):
+    def run_setup(self, uid, pacman):
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            bin_dir = root / "bin"
+            bin_dir.mkdir()
+            stubs = {"id": "echo %d" % uid, "curl": "exit 7", "pacman": pacman, "pacman-key": "exit 0"}
+            for name, body in stubs.items():
+                (bin_dir / name).write_text("#!/bin/sh\n%s\n" % body)
+                (bin_dir / name).chmod(0o755)
+            script = root / "setup"
+            script.write_text(SCRIPT.read_text().replace("WORK=/var/cache/droiddeck-flatpak", "WORK=%s/work" % root)
+                              .replace("/etc/pacman.d/gnupg/pubring.gpg", str(root / "pubring.gpg"))
+                              .replace("    /etc/pacman.conf >", "    %s >" % (root / "pacman.conf")))
+            (root / "pacman.conf").write_text("[options]\n[core]\nInclude = /etc/pacman.d/mirrorlist\n")
+            (root / "pubring.gpg").write_text("")
+            env = dict(os.environ, PATH="%s:%s" % (bin_dir, os.environ["PATH"]))
+            result = subprocess.run(["bash", str(script)], env=env, capture_output=True, text=True, timeout=30)
+            return result.returncode, result.stdout
+
+    def test_a_manual_run_without_root_says_so(self):
+        code, out = self.run_setup(1000, "exit 0")
+        self.assertEqual(code, 1)
+        self.assertIn("== FAIL needs root", out)
+        self.assertNotIn("Reading the package lists", out)
+
+    def test_an_unreachable_mirror_reports_pacmans_error(self):
+        code, out = self.run_setup(0, "echo \"error: failed retrieving file 'core.db' : Could not resolve host\" >&2; exit 1")
+        self.assertEqual(code, 1)
+        self.assertIn("== FAIL could not reach the Arch Linux ARM mirrors (error: failed retrieving file 'core.db' : "
+                      "Could not resolve host)", out)
+
+
+if __name__ == "__main__":
+    unittest.main()