nCdy/boot-update — comment on commit 4c12164b1ca9bc60f680dded8287234fb182f2b9
File: python/modules/funtoo/core/config.py line 175
By kini:

This works in Python 2.x (though deprecated) but is prohibited in 3.x. The correct way to raise this exception is to call the `__init__` method of `ConfigFileError`:

raise ConfigFileError("Duplicate config file section \"%s\" on line %s" % (section, ln+1))

Because `%` is sort of discouraged these days (there were at one point plans to remove it from Python 3.1), even better would be

raise ConfigFileError('Duplicate config file section "{0}" on line {1}'.format(section, ln+1))