[root@99f2a9044ed6 /]# git clone https://git.centos.org/centos-git-common.git
Cloning into 'centos-git-common'...
remote: Enumerating objects: 265, done.
remote: Counting objects: 100% (265/265), done.
remote: Compressing objects: 100% (258/258), done.
remote: Total 265 (delta 50), reused 213 (delta 3), pack-reused 0
Receiving objects: 100% (265/265), 132.61 KiB | 2.21 MiB/s, done.
Resolving deltas: 100% (50/50), done.

[root@99f2a9044ed6 /]# git clone https://git.centos.org/rpms/openssl.git
Cloning into 'openssl'...
remote: Enumerating objects: 849, done.
remote: Counting objects: 100% (849/849), done.
remote: Compressing objects: 100% (783/783), done.
remote: Total 849 (delta 169), reused 406 (delta 0), pack-reused 0
Receiving objects: 100% (849/849), 2.11 MiB | 10.76 MiB/s, done.
Resolving deltas: 100% (169/169), done.

[root@99f2a9044ed6 /]# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
[root@99f2a9044ed6 /]# PATH=$PATH:${PWD}centos-git-common
[root@99f2a9044ed6 /]# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/centos-git-common

[root@99f2a9044ed6 /]# cd openssl/
[root@99f2a9044ed6 openssl]# into_srpm.sh -b c8s -c imports/c8s/openssl-1.1.1k-9.el8
You need get_sources.sh from centos-git-common in PATH

[root@99f2a9044ed6 openssl]# chmod a+x ../centos-git-common/get_sources.sh 
[root@99f2a9044ed6 openssl]# into_srpm.sh -b c8s -c imports/c8s/openssl-1.1.1k-9.el8
Already on 'c8s'
Your branch is up to date with 'origin/c8s'.
Note: switching to 'imports/c8s/openssl-1.1.1k-9.el8'.

# ... etc ...