Gimp 2.10.10 build for OSX unable to be started using the command line using relative path

GIMP version: gimp-2.10.10-x86_64.dmg

Operating System: OS X High Sierra (10.13.6)

Package: Official DMG

Description of the bug

When attempting to start gimp using the command line, the app fails to start with errors that the babl installation seems broken.

Reproduction

Is the bug reproducible? Always

Reproduction steps:

1. Install gimp to user Desktop/ folder (probably the same for other locations too)
2. Attempt to run gimp start script from a different directory (like the user home directory)

> ./Desktop/GIMP-2.10.app/Contents/MacOS/gimp

Expected result: If the gimp script is started from the directory where the shell script resides, this is the console output:

> ./gimp
2019-04-23 00:38:51.236 gimp-bin[51904:12074445] *** WARNING: Method userSpaceScaleFactor in class NSView is deprecated on 10.7 and later. It should not be used in new applications. Use convertRectToBacking: instead. 
Cannot spawn a message bus without a machine-id: Unable to load /var/lib/dbus/machine-id or /etc/machine-id: Failed to open file “/var/lib/dbus/machine-id”: No such file or directory
GIMP-Error: Unable to run plug-in "spyro_plus.py"
(/Users/user/Desktop/GIMP-2.10.app/Contents/Resources/lib/gimp/2.0/plug-ins/spyro_plus.py)

Failed to execute child process “/Users/user/Desktop/GIMP-2.10.app/Contents/Resources/lib/gimp/2.0/plug-ins/spyro_plus.py” (Exec format error)


(gimp-bin:51904): GLib-GObject-WARNING **: 00:38:53.694: invalid cast from 'GtkMenuBar' to 'GtkWindow'

(gimp-bin:51904): Gtk-CRITICAL **: 00:38:53.694: gtk_window_add_accel_group: assertion 'GTK_IS_WINDOW (window)' failed

Actual result: If gimp is started from a different directory, this is the console output:

> Desktop/GIMP-2.10.app/Contents/MacOS/gimp
babl-extension.c:354 void babl_extension_load_dir_list(const char *)()
        WARNING: the babl installation seems broken, no extensions found in queried
BABL_PATH (Desktop/GIMP-2.10.app/Contents/MacOS/../Resources/lib/babl-0.1) this means no SIMD/instructions/special case fast paths and
only slow reference conversions are available, applications might still
run but software relying on babl for conversions will be slow

2019-04-23 00:41:23.631 gimp-bin[51953:12075513] *** WARNING: Method userSpaceScaleFactor in class NSView is deprecated on 10.7 and later. It should not be used in new applications. Use convertRectToBacking: instead. 
Cannot spawn a message bus without a machine-id: Unable to load /var/lib/dbus/machine-id or /etc/machine-id: Failed to open file “/var/lib/dbus/machine-id”: No such file or directory
babl-format.c:712 const Babl *babl_format(const char *)()
        const Babl *babl_format(const char *)("CIE Lab double"): not found
sh: gdb: command not found

Additional information

This problem seems to be worked around by simply making the BASEDIR variable within the gimp shell script be fully pathed by adding something like the following after the cd "$BASEDIR" command in the gimp shell script:

BASEDIR=`pwd`