update_potfiles.sh does not include some files.

[ghost]

I have tried to update my .po files via update_potfiles.sh. It creates a .pot file which does not include these files. It seems that update_potfiles.sh does not create these files

autorecover.glade.h
inktool.glade.h
layervis.glade.h
preferenceswindow.glade.h
brusheditor.glade.h
layerprops.glade.h
mypaint.glade.h
resources.xml.h

Basic system details

MyPaint version: [ git master]
Operating system: [Ubuntu 18.04.2]
Desktop environment: [ GNOME 3.28.3]

Steps to reproduce

1. Download the master source code via GitHub.
2. Go to the po/ folder.
3. Check mypaint.pot files (There will be more than 5400 lines)
4. Mark update_potfiles.sh as executable than double click to run.
5. Check mypaint.pot files again (There would be less than 3500 lines)

Backtraces or error messages

Extracting strings from ../gui/resources.xml...
Generating C format header file for translation.
Wrote ../gui/resources.xml.h
warning: intltool-extract did not create tmp/resources.xml.h
Extracting strings from ../gui/autorecover.glade...
Generating C format header file for translation.
Wrote ../gui/autorecover.glade.h
warning: intltool-extract did not create tmp/autorecover.glade.h
Extracting strings from ../gui/brusheditor.glade...
Generating C format header file for translation.
Wrote ../gui/brusheditor.glade.h
warning: intltool-extract did not create tmp/brusheditor.glade.h
Extracting strings from ../gui/inktool.glade...
Generating C format header file for translation.
Wrote ../gui/inktool.glade.h
warning: intltool-extract did not create tmp/inktool.glade.h
Extracting strings from ../gui/layerprops.glade...
Generating C format header file for translation.
Wrote ../gui/layerprops.glade.h
warning: intltool-extract did not create tmp/layerprops.glade.h
Extracting strings from ../gui/layervis.glade...
Generating C format header file for translation.
Wrote ../gui/layervis.glade.h
warning: intltool-extract did not create tmp/layervis.glade.h
Extracting strings from ../gui/mypaint.glade...
Generating C format header file for translation.
Wrote ../gui/mypaint.glade.h
warning: intltool-extract did not create tmp/mypaint.glade.h
Extracting strings from ../gui/preferenceswindow.glade...
Generating C format header file for translation.
Wrote ../gui/preferenceswindow.glade.h
warning: intltool-extract did not create tmp/preferenceswindow.glade.h
Building mypaint-my.pot...
Running xgettext --add-comments --directory=. --directory=. --default-domain=mypaint-my --flag=g_strdup_printf:1:c-format --flag=g_string_printf:2:c-format --flag=g_string_append_printf:2:c-format --flag=g_error_new:3:c-format --flag=g_set_error:4:c-format --flag=g_markup_printf_escaped:1:c-format --flag=g_log:3:c-format --flag=g_print:1:c-format --flag=g_printerr:1:c-format --flag=g_printf:1:c-format --flag=g_fprintf:2:c-format --flag=g_sprintf:2:c-format --flag=g_snprintf:3:c-format --flag=g_scanner_error:2:c-format --flag=g_scanner_warn:2:c-format --output=mypaint-my.pot --files-from=./POTFILES.in.temp --keyword=_ --keyword=N_ --keyword=C_:1c,2 --keyword=NC_:1c,2 --keyword=Q_ --keyword=g_dgettext:2 --keyword=g_dngettext:2,3 --keyword=g_dpgettext:2 --keyword=g_dpgettext2=2c,3 --from-code=UTF-8
Removing generated header (.h) files...done.
Wrote mypaint-my.pot