Manual package creation and testing¶
create approach using
test_package subfolder, is not strictly necessary, though very strongly recommended.
If we didn’t want to use the
test_package functionality, we could just write our recipe ourselves or use the
conan new command without the
-t command line argument.
$ mkdir mypkg && cd mypkg $ conan new Hello/0.1
This will create just the
conanfile.py recipe file. Now we could create our package:
$ conan create demo/testing
This would be equivalent to:
$ conan export demo/testing $ conan install Hello/0.1@demo/testing --build=Hello
Once the package is there, it can be consumed like any other package, just add
Hello/0.1@demo/testing to some project
conanfile.py requirements and run:
$ conan install . # build and run your project to ensure the package works
The package creation process¶
It is very useful for package creators and conan users in general to understand the flow of package creation inside the conan local cache, and its layout.
For every package recipe, there are 5 important folders in the conan local cache:
- export: The folder where the package recipe is stored.
- export_source: The folder where code copied with the recipe
exports_sourcesattribute is stored.
- source: Where the source code for building from sources is stored.
- build: Where the actual compilation of sources is done. There will typically be one subfolder for each different binary configuration
- package: Where the final package artifacts are stored. There will be one subfolder for each different binary configuration
The “source” and “build” folders only exist when the packages have been built from sources.
The process starts when a package is “exported”, via the
conan export command or more typically, with the
conan create command. The conanfile.py and files specified by the
exports_sources field are copied from the user space into the conan local cache.
The “export” and “export_source” files are copied to the “source” folder, and then the
source() method is executed (if existing). Note that there is only one source folder for all the binary packages. If some source code is to be generated that will be different for different configurations, it cannot be generated in the
source() method, it has to be done in the
Then, for each different configuration of settings and options, a package ID will be computed in the form of a SHA-1 hash of such configuration. Sources will be copied to the “build/hashXXX” folder, and the
build() method will be triggered.
After that, the
package() method will be called to copy artifacts from the “build/hashXXX” folder to the “package/hashXXX” folder.
package_info() methods of all dependencies will be called and gathered to be able to generate files for the consumer build system, as the
conanbuildinfo.cmake for the
cmake generator. Also the
imports feature will copy artifacts from the local cache into user space if specified.