ERROR: Error executing a python function in <code>:####         | ETA:  00:00:05

The stack trace of python calls that resulted in this exception/failure was:
File: '<code>', lineno: 10, function: <module>
     0006:__anon_35__var_build_meta_classes_devshell_bbclass(d)
     0007:__anon_78__var_build_meta_classes_sstate_bbclass(d)
     0008:__anon_45__var_build_meta_classes_blacklist_bbclass(d)
     0009:__anon_140__var_build_meta_classes_siteinfo_bbclass(d)
 *** 0010:__anon_35__var_build_meta_recipes_support_libproxy_libproxy_0_4_11_bb(d)
File: '__anon_35__var_build_meta_recipes_support_libproxy_libproxy_0_4_11_bb', lineno: 2, function: __anon_35__var_build_meta_recipes_support_libproxy_libproxy_0_4_11_bb
     0001:def __anon_35__var_build_meta_recipes_support_libproxy_libproxy_0_4_11_bb(d):
 *** 0002:    if incompatible_license_contains("GPLv3", "x", "", d) == "x" or bb.utils.contains("DISTRO_FEATURES", "x11", "x", "", d) == "":
     0003:        d.setVar("EXTRA_OECMAKE", d.getVar("EXTRA_OECMAKE").replace("-DWITH_GNOME=yes", "-DWITH_GNOME=no"))
     0004:        d.setVar("DEPENDS", " ".join(i for i in d.getVar("DEPENDS").split() if i != "gconf"))
     0005:
File: 'license.bbclass', lineno: 4, function: incompatible_license_contains
     0001:def incompatible_license_contains(license, truevalue, falsevalue, d):
     0002:    license = canonical_license(d, license)
     0003:    bad_licenses = (d.getVar('INCOMPATIBLE_LICENSE', True) or "").split()
 *** 0004:    bad_licenses = expand_wildcard_licenses(d, bad_licenses)
     0005:    return truevalue if license in bad_licenses else falsevalue
     0006:
File: 'license.bbclass', lineno: 8, function: expand_wildcard_licenses
     0004:    wildcards from SPDXLICENSEMAP flags and SRC_DISTRIBUTE_LICENSES values.
     0005:    """
     0006:    import fnmatch
     0007:    licenses = []
 *** 0008:    spdxmapkeys = d.getVarFlags('SPDXLICENSEMAP').keys()
     0009:    for wld_lic in wildcard_licenses:
     0010:        spdxflags = fnmatch.filter(spdxmapkeys, wld_lic)
     0011:        licenses += [d.getVarFlag('SPDXLICENSEMAP', flag) for flag in spdxflags]
     0012:
Exception: AttributeError: 'NoneType' object has no attribute 'keys'

ERROR: Failed to parse recipe: /var/build/meta/recipes-support/libproxy/libproxy_0.4.11.bb