file RENAME not behaving as expected

Code
1

Hi,

the RENAME functionality of the file command is not behaving as expected. I have a small reproducer right here:

set(old_name "file.txt") 
set(new_name "new_file.txt") 

message("Pre rename:") 
execute_process(COMMAND ls) 

file(RENAME "${old_name}" "${new_name}" NO_REPLACE) 

message("\nPost rename:") 
execute_process(COMMAND ls)

Running this via cmake -P <script name> produces the following output:

Pre rename: 
file.txt 
script.cmake 

Post rename: 
file.txt 
new_file.txt 
script.cmake

According to the docs, the file should be moved and not copied. This problem only occurs when I pass NO_REPLACE in the arguments. If I remove that extra argument, the command behaves as expected. Am I misunderstanding the NO_REPLACE option or is this a bug?

The background for even noticing this is my usage of ExternalData. Post download, the files are “moved” with file(RENAME ... NO_REPLACE). But this also just leads to a copy, so I end up with duplicates of very large files on my filesystem.

2

That’s unexpected. Please open an issue in the issue tracker. Be sure to mention the platform(s) you’re seeing this on, and what CMake versions exhibit the behavior.

For reference, the NO_REPLACE option was implemented by MR 5877 and first appeared in CMake 3.21.