When launching the bitbake -g -u taskexp to show task dependencies at UI, the following stack trace shows at command line in my opensuse box.

$ bitbake -g -u taskexp core-image-minimal
Traceback (most recent call last):
  File "/home/lsandov1/poky-testing/poky/bitbake/bin/bitbake", line 48, in <module>
    cookerdata.CookerConfiguration()))
  File "/home/lsandov1/poky-testing/poky/bitbake/lib/bb/main.py", line 372, in bitbake_main
    server_connection, ui_module = setup_bitbake(configParams, configuration)
  File "/home/lsandov1/poky-testing/poky/bitbake/lib/bb/main.py", line 413, in setup_bitbake
    ui_module = import_extension_module(bb.ui, configParams.ui, 'main')
  File "/home/lsandov1/poky-testing/poky/bitbake/lib/bb/main.py", line 106, in import_extension_module
    module = __import__(pkg.__name__, fromlist=[modulename])
  File "/home/lsandov1/poky-testing/poky/bitbake/lib/bb/ui/taskexp.py", line 21, in <module>
    import gi
ImportError: No module named 'gi'
DEBUG: Removed the following variables from the environment: OLDPWD, MINICOM, LS_COLORS, XDG_RUNTIME_DIR, gopher_proxy, LESS, XKEYSYMDB, LESSKEY, HISTSIZE, LS_OPTIONS, HOSTTYPE, SSH_CLIENT, LESS_ADVANCED_PREPROCESSOR, XDG_DATA_DIRS, LIBGL_DEBUG, BUILDDIR, MORE, XDG_CONFIG_DIRS, SSH_SENDS_LOCALE, MACHTYPE, G_FILENAME_ENCODING, FROM_HEADER, HOST, MANPATH, SOCKS5_SERVER, PYTHONSTARTUP, HOSTNAME, SSH_CONNECTION, CSHEDIT, MAIL, OSTYPE, PAGER, SHLVL, LESSCLOSE, INPUTRC, GPG_TTY, SOCKS_PROXY, XNLSPATH, PROFILEREAD, socks_proxy, XDG_SESSION_ID, SSH_TTY, CPU, LESSOPEN, NNTPSERVER, LANG, COLORTERM, _, G_BROKEN_FILENAMES, CONFIG_SITE
lsandov1@yctb05:~/poky-testing/poky/build>