I remember we had these "ECDSA verification failure" issues in older QEMU versions, but these were fixed.
I just tired building the go file under Fedora 32 running under latest upstream qemu-system-s390x, and using latest go binaries from https://golang.org/dl/:
[root@atomic-00 hello]# uname -a
Linux atomic-00 5.8.11-200.fc32.s390x #1 SMP Wed Sep 23 13:36:15 UTC 2020 s390x s390x s390x GNU/Linux
[root@atomic-00 hello]# go version
go version go1.15.7 linux/s390x
I remember we had these "ECDSA verification failure" issues in older QEMU versions, but these were fixed.
I just tired building the go file under Fedora 32 running under latest upstream qemu-system-s390x, and using latest go binaries from https:/ /golang. org/dl/:
[root@atomic-00 hello]# uname -a 200.fc32. s390x #1 SMP Wed Sep 23 13:36:15 UTC 2020 s390x s390x s390x GNU/Linux
Linux atomic-00 5.8.11-
[root@atomic-00 hello]# go version
go version go1.15.7 linux/s390x
[root@atomic-00 hello]# go build 20170915032832- 14c0d48ead0c
go: downloading rsc.io/quote v1.5.2
go: downloading rsc.io/sampler v1.3.0
go: downloading golang.org/x/text v0.0.0-
[root@atomic-00 hello]# ./hello
Hello, world.
Can you double check that you are really using latest upstream QEMU in your more-advanced cross-build?