as far as I can see, the push to mbedtls 2.4.2 broke the patch that is applied on top of that repository. I'm seeing 100% of the builders fail now, with these sorts of messages:
17:47:25 HEAD is now at 59ae96f Updated version number to 2.4.2 for release 17:47:25 error: patch failed: library/net_sockets.c:321 17:47:25 error: library/net_sockets.c: patch does not apply 17:47:25 error: patch failed: library/x509_crt.c:1122 17:47:25 error: library/x509_crt.c: patch does not apply 17:47:25 scons: *** mbedtls: issue on applying patch: 256 Stop.
