Re: tangle option to not write a file with same contents?

[Max Nikulin <manikulin@gmail.com>]

A couple additional notes for the case that someone will find this 
thread in future.

On 28/10/2021 11:04, Greg Minshall wrote:
> 
> i wonder if it would be reasonable to add an option such that, when
> tangling, `org-babel-tangle` would not write a file with the
> already-existing contents of the target file?
> 
> this would be helpful, e.g., for those of us who use make(1)-based work
> flows.

It was not obvious for me earlier that it should be namely an *option*, 
not just change of behavior, since e.g. `org-babel-load-file' relies on 
timestamp comparison of the source .org file and the derived .el file. I 
am unsure concerning default value of such setting.

It was an issue with `org-file-newer-than-p' that reminded me about this 
thread.

P.S. Timestamp comparison is not always reliable to determine whether 
prerequisite has not been updated. Earlier python had timestamp of .py 
file saved in the header of compiled .pyc files, but at some moment they 
switched to hash.

https://peps.python.org/pep-0552/
PEP 552 – Deterministic pycs