Can't not find /proc/version on rpmbuild mock enviroment

#jtreg -version
grep: /proc/version: No such file or directory
jtreg 7.4-dev+0
Installed in /builddir/build/BUILD/jtreg/lib/jtreg.jar
Running on platform version 24 from /builddir/build/BUILD/jdk-binary.
Built with Java(TM) 2 SDK, Version 11.0.21+9-LTS on June 14, 2024.
Copyright (c) 1999, 2022, Oracle and/or its affiliates. All rights reserved.
Use is subject to license terms.
JT Harness, version 6.0 ea b24 (June 14, 2024)
Java Assembler Tools, version 7.0 ea b09 (June 14, 2024)
TestNG: testng-7.3.0.jar, guice-5.1.0.jar, jcommander-1.82.jar
JUnit: junit-platform-console-standalone-1.10.2.jar