ID 508193 - File paths containing square brackets error when using path substitution.

Problem summary
File paths containing square brackets error when using path substitution.
 
Customer reported version
nuke.12.2v3
 
Customer reported platform
ubuntu
 
Steps to reproduce
1) In the Command Prompt/Terminal, set an environment variable for a location to some footage. i.e set footage=/path/to/folder/
2) In Nuke, Read in the file with R and choose it from the file path.
3) In the file knob, substitute the file path with the environment variable by using square brackets: [footage]/file.exr
 

Expected behavior
Path substitution should occur and the file should be displayed in the Viewer without errors.
 
Actual behavior
An error is given in the Viewer and the path is not substituted.
 
Workaround
There is no available workaround at this time.
 
Reproduced by Support in:
Nuke 13.2v1 - Windows 10, CentOS 7
Nuke 13.1v1 - Windows 10
Nuke 13.0v1 - Windows 10
Nuke 12.0v1 - Windows 10
Nuke 11.0v1 - Windows 10
Nuke 10.0v1 - Windows 10
Nuke 9.0v1 - Windows 10, CentOS 7
 
Earliest version tested
Nuke 9.0v1 - This issue appears to be in all versions of the product