In same cases it can happen that env. vars. are not expanded in a consistent way, when some variables are expanded and some aren't.

Reproducer:
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Setup parametrized build with 3 string parameters:
A="aaa"
C="ccc"
B=$A$C
and add shell build step which prints B parameter
echo $B

Output is aaa$C, while one would expect aaaccc (or $A$C).

This is caused by Launcher.inherit() method, which adds variables into resolver and eventually expand them in the same loop (on alphabetically sorted map), thus when expanding $B, $A is already in resolver and gets expanded, while $C is not there yet and thus remains unexpanded.