| CMP0135 |
| ------- |
| |
| .. versionadded:: 3.24 |
| |
| When using the ``URL`` download method with the :command:`ExternalProject_Add` |
| command, CMake 3.23 and below sets the timestamps of the extracted contents |
| to the same as the timestamps in the archive. When the ``URL`` changes, the |
| new archive is downloaded and extracted, but the timestamps of the extracted |
| contents might not be newer than the previous contents. Anything that depends |
| on the extracted contents might not be rebuilt, even though the contents may |
| change. |
| |
| CMake 3.24 and above prefers to set the timestamps of all extracted contents |
| to the time of the extraction. This ensures that anything that depends on the |
| extracted contents will be rebuilt whenever the ``URL`` changes. |
| |
| The ``DOWNLOAD_EXTRACT_TIMESTAMP`` option to the |
| :command:`ExternalProject_Add` command can be used to explicitly specify how |
| timestamps should be handled. When ``DOWNLOAD_EXTRACT_TIMESTAMP`` is not |
| given, this policy controls the default behavior. The ``OLD`` behavior for |
| this policy is to restore the timestamps from the archive. The ``NEW`` |
| behavior sets the timestamps of extracted contents to the time of extraction. |
| |
| This policy was introduced in CMake version 3.24. CMake version |release| |
| warns when the policy is not set and uses ``OLD`` behavior. Use the |
| :command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly. |
| |
| .. include:: DEPRECATED.txt |
