I found there is no such pkgs from RHEL8 repo, but it is required by others when rebuild pkgs, eg. rebuild rng-tools.
Not know much about the background of missing this pkg, but if it is expected, I am wondering where user can get libsysfs-devel pkg except 'BaseOS' and 'AppStream'.

[root@reserved-66-92-226 rpmbuild]#  rpmbuild -ba --target=$(uname -m) /root/rpmbuild/SPECS/rng-tools.spec
Building target platforms: x86_64
Building for target x86_64
error: Failed build dependencies:
libsysfs-devel is needed by rng-tools-6.8-2.el8.x86_64

[root@reserved-66-92-226 rpmbuild]# yum search libsysfs-devel
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No matches found.

Version-Release number of selected component (if applicable):

RHEL Version:
RHEL8.2(4.18.0-151.el8.x86_64)

How reproducible:
100%

Steps to Reproduce:
1. Start a RHEL8.2 .
2. Try to install libsysfs-devel.

Actual results:
No libsysfs-devel found.

Expected results:
All dependencies are expected in the repo.

Additional info:
- N/A