I noticed that some external projects were being reconfigured/built
with every make, even though no files in the external project had been
updated.
With some debugging I noticed that git based external projects were
re-running their "update" step every time, and that in turn caused the
configure/build/install steps to re-run as well. (Generally the build
step is a no-op as the Makefile/etc. in the external project is well
formed and doesn't do anything, but the configure/install steps still
run).
It seems related to this cmake bug:
https://gitlab.kitware.com/cmake/cmake/-/issues/19703. In short, the
git update step for an external project does not create any "done"
file that denotes that the files are still up-to-date. Without that
"done" file, the update step is always run, and that in turn causes
the other steps for the external project to re-run as well.
The best way to fix this seems to be to skip the update step by
defining an empty UPDATE_COMMAND. As long as the downloaded code for a
given hash/tag/etc does not change, the update step is unnecessary.
And if we *really* wanted to ensure unchanged dependencies, we would
download our own copies anyway.
Making this change significantly cleans up the falco build to avoid
rebuilding git based external dependencies.
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
The CMake module downloads `string-view-lite` from
https://github.com/martinmoene/string-view-lite
It is a single-file header-only version of C++17-like `string_view` for
C++98, C++03, C++11, and later.
Notices it also provides C++20 extensions like:
- empty()
- starts_with()
- ends_with()
- etc.
Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>
