我打入pkg-config --list-all 时出现这样的错误,请问怎样解决?
Package gtk+-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtk+-2.0.pc'
to the PKG_CONFIG_PATH environment variable
Package 'gtk+-2.0', required by 'libpanel-applet-2', not found