Comment # 1 on bug 1221361 from Giacomo Comes

There is an error in /etc/profile.d/alljava.csh (leap 15.5).
The line:
  set ALTERNATIVES_JAVA_LINK=`realpath /etc/alternatives/java 2> /dev/null`
does not work because the c shell does not support std-error redirection.
The error causes ALTERNATIVES_JAVA_LINK to be empty and that makes also
the variables: JRE_HOME, JAVA_HOME, JDK_HOME and SDK_HOME empty as well.

The bug is present in the file:
  git-47-056fc66c699a8544c7692a03c905fca568f5390b.patch
in the leap 15.5 source package.

Funny enough, the same file in the leap 15.6 source package is without the bug.
Therefore there is no issue on leap 15.6

Tumbleweed instead has incorporated the faulty patch and the file:
  aaa_base-84.87+git20180409.04c9dae/files/etc/profile.d/alljava.csh
in the source tar file: aaa_base-84.87+git20180409.04c9dae.tar.xz
contains the same bug as leap 15.5.