If I have a project, which has:

1. /CMakeLists.txt:

   ```cmake
   cmake_minimum_required(VERSION 3.29)
   project(test)
   include(./cmake/CPM.cmake)
   add_subdirectory(subdir)
   cpmfindpackage(
     NAME
     nlohmann_json
     VERSION
     3.11.2
     URL
     "https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz"
     EXCLUDE_FROM_ALL
     ON)

   if(NOT TARGET nlohmann_json::nlohmann_json)
     message(FATAL_ERROR "BUG")
   endif()
   ```
2. /subdir/CMakeLists.txt

   ```cmake
   cpmfindpackage(
     NAME
     nlohmann_json
     VERSION
     3.11.2
     URL
     "https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz"
     EXCLUDE_FROM_ALL
     ON)
   ```

When nlohmann_json is first founded by find_package,
CPM.cmake register this package and later call to CPMFindPackage will
not actually perform a find_package again, which leads to this buggy
behavior.

As CPM write a FindXXX.cmake file for packages added by CPM to pervert
find_package to get local package, I think directly use cpm_find_package
to check if a package is already added is good enough.

* Add xxHash example

* Fix link error

* run code formatters

---------

Co-authored-by: Lars Melchior <[email protected]>

* Custom cache directory name

Enable setting a custom directory name for cached packages.
Required if e.g. patch_command uses external variables or
just to set a human readable name.

* fixup! review comment CUSTOM_CACHE_DIR -> CUSTOM_CACHE_KEY

* run cmake-format

---------

Co-authored-by: Olsson Gerhard <[email protected]>
Co-authored-by: Lars Melchior <[email protected]>

* Remove 'bug' from comment

* Fix the styling

Oh gosh, I messed up the style...

* Line endings

* Adding PATCHES keyword.

* Formatting fix.

* Move cpm_add_patches() outside if/else scopes.

* cmake-format: add PATCHES to CPMAddPackage.

* Integration tests for PATCHES command.

* Use get_filename_component() in place of cmake_path() for use with all cmake versions 3.14 and above.

* Added an example and improved comment for cpm_add_patches.

* replace deprecated calls to FetchContent_Populate

The single argument signature for FetchContent_Populate is deprecated with CMake 3.30.
It was used, in order to call add_subdirectory manually with the EXCLUDE_FROM_ALL and SYSTEM flags.
These have been added to FetchContent_Declare with 3.25 and 3.28.
Calling FetchContent_MakeAvailable will internally call add_subdirectory with EXCLUDE_FROM_ALL and SYSTEM.
There is therefore no need to call this manually.

* fix: OPTIONS passed to CPMAddPackage not set

where previously parsed in cpm_add_subdirectory which is not called
on the new code path.

* refactor: remove an unnecessary else branch

* ci: include cmake 3.30 in test matrix

* fix: forward SOURCE_SUBDIR to FetchContent_Declare

For CMake version <3.28 this is done by calling add_subdirectory manually.
For newer version FetchContent_Declare/MakeAvailable handles this for us.

* fix: only set options if download_only is false

this replicates the old behaviour

* fix: DOWNLOAD_ONLY test

* refactor: always use *_Populate to reduce code paths

* Revert "refactor: always use *_Populate to reduce code paths"

This reverts commit 0e8ca2a.

---------

Co-authored-by: Avus <[email protected]>

* Additional search path for patch.exe

* Style

…) (cpm-cmake#604)

Co-authored-by: Avus <[email protected]>

* Update to v1.85.0

* Boost example to 1.86

…CHE is unset. (cpm-cmake#580)

…ake#627)

`WIN32` checks whether current build context is windows. This is not correct in case of cross-compiling, because we are interested in finding host's tools, not SDK's tools.

* trigger CI to see if sol2 example is reliably failing

* attempt patch from github comment

* fix patch

* add info to comment on patch

* run fix-format

* simplify patchfile

Co-authored-by: Lars Melchior <[email protected]>

* Add git_archival mechanism

* fetch_content

* Delete .pre-commit-config.yaml

* Update CPM.cmake

* cmake-format

Co-authored-by: Avus <[email protected]>

…pm-cmake#617)

* feature: add URI to use shorthand syntax with additional options

This allows to combine the shorthand syntax with URI and additional arguments:
```
CPMAddPackage(URI "gh:nlohmann/[email protected]" OPTIONS "JSON_BUildTests OFF")
```

This is much shorter than the longer syntax way of writing:
```
CPMAddPackage(
  NAME nlohmann_json
  VERSION 3.9.1
  GITHUB_REPOSITORY nlohmann/json
  OPTIONS
    "JSON_BuildTests OFF"
)
```

* fix: use shorthand syntax in examples

* test: add test for shorthand syntax with options

* doc: extend README mentioning shorthand syntax with options

* feat: URI keyword also sets EXCLUDE_FROM AND SYSTEM

* doc: more explicit about the behavior of URI

* doc: adjust README accordingly to PR-Review

* test: fix inline documentation of test_simple

* move URI comment

* added new test for shorthand syntax

* reset simple test

* add that URI must be the first argument

---------

Co-authored-by: Lars Melchior <[email protected]>

…m-cmake#631)

* Add ASSERT_CONTENTS_EQUAL test macro in testing.cmake

Checks if the contents of a file matches the given input

* Use shorter hashes with CPM_SOURCE_CACHE (cpm-cmake#624)

Uses shorter hashes with CPM_SOURCE_CACHE. Falls back to a longer hash
if necessary (ie, if there's a collision with an existing hash).

See: cpm-cmake#624

* Update integration tests to support shorter hashes

* trigger ci

* run cmake-format

* if already available, use the legacy cache hash

* create temporary file in current binary dir

* add test case for legacy hash

---------

Co-authored-by: Lars Melchior <[email protected]>
Co-authored-by: Lars Melchior <[email protected]>