Even though the `file(GLOB)` documentation specifically warns against
using it to collect a list of source files, projects often do it anyway.
Since it uses `readdir()`, the list of files will be unsorted.
This list is often passed directly to add_executable / add_library.
Linking binaries with an unsorted list will make it unreproducible,
which means that the produced binary will differ depending on the
unpredictable `readdir()` order.
To solve those reproducibility issues in a lot of programs (which don't
explicitly `list(SORT)` the list manually), sort the resulting list of
the `file(GLOB)` command.
A more detailed rationale about reproducible builds is available
[here](https://reproducible-builds.org/).
Although we fail with an error on a hash mismatch, it is not a fatal
error so the script may continue processing. If the download itself had
no error then report in the STATUS variable that the operation was not
successful due to the hash mismatch.
Suggested-by: Tobias Hieta <tobias@hieta.se>
GLOB lists directories by default and GLOB_RECURSE does not.
LIST_DIRECTORIES enables user to control the behavior explicitly for
consistently for both GLOB and GLOB_RECURSE.
Provide options to fail without blocking or to block up to a timeout.
Provide options to specify the scope containing the lock so it can be
released automatically at the end of a function, file, or process.
Extend the RunCMake.file test with cases covering the file(LOCK) command
usage and error cases.
Create options "MESSAGE_ALWAYS", "MESSAGE_LAZY", and "MESSAGE_NEVER" to
specify whether to print the "Installing" and "Up-to-date" messages.
Extend the RunCMake.file test with cases covering these options.
Teach cmFileCopier::InstallDirectory to detect whether the destination
directory exists. If so, report it as "Up-to-date" instead of
"Installing". This resolves message asymmetry with file installations.
Extend the RunCMake.file and RunCMake.install tests to check the
installation output on both the first and second run.
Suggested-by: J Decker <d3ck0r@gmail.com>
Reiner Herrmann
Brad King
Domen Vrankar
Ruslan Baratov