We've had an rsync command that has worked for quite a while (1+ years), but suddenly started getting errors after we upgraded rsync from version 3.2.3 to 3.2.7.  I'm not sure exactly which minor release broke our expectation of how environment variables are used in remote host paths, but there certainly seems to be some major change.  See the example command below in which we were protecting the remote environment variable with single quotes to ensure it resolved on the remote host and not locally.  I was able to reliable reproduce this issue with 3.2.7 and show that the command worked with 3.2.3.

Example Command:

rsync -rl /home/user/test_dir 'user@hostname:$PROJECTS_HOME/INFINITE'

3.2.7 -> rsync: mkdir "/p/home/rlarson/$PROJECTS_HOME/INFINITE" failed: No such file or directory

3.2.3 -> successful rsync

A few notes:
1. The env var and path does exist on remote system
2. "/p/home/rlarson" is my  $HOME dir on remote system
3. Both source and dest OS are Linux

Anything else I can add to help troubleshoot this issue please let me know.