Vote to keep CMP0135

Development
1

I hope, I’m in the right category.

CMP0135 allows in the old setting to keep the original timestamp when loading data e.g. as external project. https://cmake.org/cmake/help/latest/policy/CMP0135.html

Our projects has 10 to 20 external dependencies and some like boost or vtk build quite slowly. Therefore we have a home built solution for local caching of precompiled dependencies.

We extract also our precompiled dependencies via external project. The new setting of CMP0135 destroys this approach.

So I kindly vote from my side with this use case to keep CMP0135 OLD. The deprecated warning of cmake 4 scares me :(. Sure I could find a workaround, but I thought I kindly ask to keep the current state :slight_smile:

Thanks!

2

Note that the same CMake version which introduced CMP0135 also introduced the ExternalProject/FetchContent argument DOWNLOAD_EXTRACT_TIMESTAMP <bool>, which is also documented in the policy’s docs, and which gives you precise control of the timestamps’ behaviour. The policy only changes the default when you don’t specify DOWNLOAD_EXTRACT_TIMESTAMP. Your use case seems to indicate you should specify it.

1 Like
3

Thanks a lot! There is a German saying “Those who can read have a clear advantage”.

I fixed it, it was just some additional lines as we enforce not yet cmake 3.24.