Keep jsonschema at 4.17.*
jsonschema >= 4.18 requires rpds-py which requires rust. The prebuild wheels provide manylinux_2_17_x86_64 while RHEL6 only supports manylinux_2_12_x86_64 (pip debug --verbose).
https://github.com/python-jsonschema/jsonschema/commit/eb004479645a4e1f0d842e4434b909f476569dcc
Mitigates #196
Signed-off-by: Michael Hofmann mhofmann@redhat.com
Edited by Michael Hofmann