Hello,

After the recent core update, Geary fails to build. A full build log is 
attached. The relevant bit appears to be this:

```
# GLib-DEBUG: g_unix_open_pipe() called with FD_CLOEXEC; please migrate 
to using O_CLOEXEC instead
# GLib-DEBUG: g_unix_open_pipe() called with FD_CLOEXEC; please migrate 
to using O_CLOEXEC instead
ok 177 /engine/Geary.ImapDb.DatabaseTest/upgrade_0_6
not ok 178 
/engine/Geary.ImapDb.DatabaseTest/utf8_case_insensitive_collation
Bail out!
stderr:
Geary.Db-Message: 15:34:23.255: Garbage collection of IMAP database 
/tmp/guix-build-geary-44.1.drv-0/geary-imap-db-database-test-6GMHT2/geary-0.6-db/geary.db 
failed: Operation was cancelled
Geary.ImapDb.DatabaseTest/utf8_case_insensitive_collation: “á” != 
“BB”
```

The related code in the source tree is at 
`test/engine/imap-db-database-test.vala` and specifically the function 
`utf8_case_insensitive_collation` which is:

```
    public void utf8_case_insensitive_collation() throws GLib.Error {
        Database db = new Database(
            this.tmp_dir.get_child("test.db"),
            GLib.File.new_for_path(_SOURCE_ROOT_DIR).get_child("sql"),
            this.tmp_dir.get_child("attachments"),
            new 
Geary.SimpleProgressMonitor(Geary.ProgressType.DB_UPGRADE),
            new 
Geary.SimpleProgressMonitor(Geary.ProgressType.DB_VACUUM)
        );

        db.open.begin(
            Geary.Db.DatabaseFlags.CREATE_FILE, null,
            this.async_completion
        );
        db.open.end(async_result());

        db.exec("""
            CREATE TABLE Test (id INTEGER PRIMARY KEY, test_str TEXT);
            INSERT INTO Test (test_str) VALUES ('a');
            INSERT INTO Test (test_str) VALUES ('b');
            INSERT INTO Test (test_str) VALUES ('B');
            INSERT INTO Test (test_str) VALUES ('BB');
            INSERT INTO Test (test_str) VALUES ('á');
        """);

        string[] expected = { "BB", "B", "b", "á", "a" };
        Db.Result result = db.query(
            "SELECT test_str FROM Test ORDER BY test_str COLLATE 
UTF8COLL DESC"
        );

        int i = 0;
        while (!result.finished) {
            assert_true(i < expected.length, "Too many rows");
            assert_equal(result.string_at(0), expected[i]);
            i++;
            result.next();
        }
        assert_true(i == expected.length, "Not enough rows");

        // Need to close it again to stop the GC process running
        db.close();
    }

```

Best,
Juli