While running make check I had an error for mappedfile that I could 'correct' by creating the directory $HOME/.cache just before running the test.

Note: OS is labeled as AIX - because that is what I have tested. I suspect it is "All"

michael@x065:[/data/prj/gnome/glib/glib-2.43.3]cd glib
michael@x065:[/data/prj/gnome/glib/glib-2.43.3/glib]tests/.libs/mappedfile
/mappedfile/basic: OK
/mappedfile/empty: OK
/mappedfile/device: OK
/mappedfile/nonexisting: OK
/mappedfile/writable: **
GLib:ERROR:mappedfile.c:93:test_writable: assertion failed (error == NULL): Failed to create file '/home/michael/.cache/glib-test-4096-random-bytes.PIH6SX': No such file or directory (g-file-error-quark, 4)
IOT/Abort trap(coredump)

# Assumption is that $HOME/.cache already exists
michael@x065:[/data/prj/gnome/glib/glib-2.43.3/glib]mkdir $HOME/.cache
michael@x065:[/data/prj/gnome/glib/glib-2.43.3/glib]tests/.libs/mappedfile
/mappedfile/basic: OK
/mappedfile/empty: OK
/mappedfile/device: OK
/mappedfile/nonexisting: OK
/mappedfile/writable: OK
/mappedfile/writable_fd: OK
/mappedfile/gbytes: OK

I cannot determine if the test is to blame (e.g., two different filenames) or if the behavior g_set_file_contents() (actually it dependencies - if it creates the file by default, why not the complete path?)

Correcting the test by checking for the existence of $HOME/.cache and creating it would help the test, but not applications dependent on g_set_file_contents() when $HOME/.cache does not exist.

As such, I cannot propose a patch - but leave this to people who know what behavior should be occurring. And, considering the two filenames - not really sure what is being tested here.

Snippet from mappedfiles

   +77  static void
   +78  test_writable (void)
   +79  {
   +80    GMappedFile *file;
   +81    GError *error = NULL;
   +82    gchar *contents;
   +83    gsize len;
   +84    const gchar *old = "MMMMMMMMMMMMMMMMMMMMMMMMM";
   +85    const gchar *new = "abcdefghijklmnopqrstuvxyz";
   +86    gchar *tmp_copy_path;
   +87
   +88    tmp_copy_path = g_build_filename (g_get_user_runtime_dir (), "glib-test-4096-random-bytes", NULL);
   +89
   +90    g_file_get_contents (g_test_get_filename (G_TEST_DIST, "4096-random-bytes", NULL), &contents, &len, &error);
   +91    g_assert_no_error (error);
   +92    g_file_set_contents (tmp_copy_path, contents, len, &error);
   +93    g_assert_no_error (error);
   +94