How to create a rpm according a exist one?

I want to create "snapd" rpm on HUAWEI's OS(openEuler OS), but I have no experience with rpmbuild. In snapd's github repository, there are many spec file for other Linux distribution like CentOS. What should I do to install snapd successfully on openEuler? It seems a total go project, may I could first go run main.go to run snapd, cause source code is also in github repository, but i got this problem:

[root@myOpenEuler2303 snapd]# go run main.go
2023/08/12 14:34:46.616748 overlord.go:272: Acquiring state lock file
2023/08/12 14:34:46.618640 overlord.go:277: Acquired state lock file
2023/08/12 14:34:46.652502 daemon.go:247: started snapd/unknown (series 16; classic; devmode) openeuler/23.03 (amd64) linux/5.4.119-20.0009.21.spr.
2023/08/12 14:34:46.673454 main.go:129: system does not fully support snapd: cannot mount squashfs image using "squashfs": mount: /tmp/syscheck-mountpoint-1047546609: mount failed: Operation not permitted.
2023/08/12 14:34:46.673504 daemon.go:340: adjusting startup timeout by 30s (pessimistic estimate of 30s plus 5s per snap)
2023/08/12 14:34:46.687999 backends.go:58: AppArmor status: apparmor not enabled
cannot run daemon: state startup errors: [cannot obtain snap-seccomp version information: fork/exec /usr/lib/snapd/snap-seccomp: no such file or directory]
exit status 1