[question] unclear how build directory is set in package() (conan 1.x)

[tclarke]

What is your question?

I'm trying to create a package which works properly when built with conan create and conan install/build/export-package. The later using "-bf" and without "-bf".

setting self.folders.build="build" works when specifying -bf build but not when running conan create. This is using self.copy("*.so", src=self.folders.build+"/lib") in package()

Changing package() to use src=self.build_folder works with conan create and the src= is the full path to the cache build folder. When using the dev workflow with -bf build it does not work. In that case the src= filed seems correct (build folder in the package directory) but it's actually build in build/build. Removing the self.folders.build line in layout() also fails as self.build_folder is the package directory (pwd when running commands) and not the build folder specified with -bf build.

I'm not sure how build_folder is being set in def package() as it seems to be ignoring the -bf option?

UPDATE: adding -of build to the conan export-pkg seems to have set self.build_folder to that value. I'm even more confused now.

Have you read the CONTRIBUTING guide?

• [x] I've read the CONTRIBUTING guide

[memsharded]

Hi @tclarke

Thanks for your question.

Please note that Conan 1.X is no longer supported. Conan 2 is more than 2.5 years old, and development and maintenance has fully stopped in Conan 1 both for the tool and ConanCenter packages, no more releases or fixes will happen.

setting self.folders.build="build" works when specifying -bf build but not when running conan create. This is using self.copy("*.so", src=self.folders.build+"/lib") in package()

It would be necessary to have a reproducible example to be able to understand and see the full issue. A couple of quick notes:

• Even in Conan 1, do not longer use self.copy(), but move to the copy(self, ...) function
• Do not use --build-folder argument, no longer necessary if using and defining a layout() method, it might be completely ignored.
• The --output-folder/-of is the Conan2 compatible way to specify a general output folder (including the build folder). But in general it shouldn't be necessary, so better try to avoid its usage if possible.

Thanks for the feedback.

[tclarke]

@memsharded I understand conan 1.x is no longer supported but I've got a project with 90+ packages and a few 100k LOC using it so converting to conan 2.x is a huge undertaking as is something as simple as converting self.copy to copy() (mostly because root_package isn't supported in copy() and we make extensive use of that). It's a dev environment completely disconnected from the Internet so the lack of ConanCenter support doesn't affect the project.

As for an example: (some extraneous stuff like imports removed for brevity). build() uses AutoToolsBuildEnvironment but I don't think that is affecting anything.

class MyLib(ConanFile):
  def layout(self):
    self.folders.source = "lib-source"
    self.cpp.package.libs = ["mylib"]
    self.cpp.package.libdirs = ["lib"]
    self.cpp.package.includedirs = ["include"]
    self.cpp.source.includedirs = ["."]
    self.cpp.build.libdirs = ["."]

  def package(self):
    libdir = os.path.join(self.build_folder, self.cpp.build.libdirs[0])
    self.copy("*.so*", src=libdir, dst="lib", keep_path=False, symlinks=True)
    self.copy("*.a", src=libdir, dst="lib", keep_path=False)
    self.copy("*.h", src=self.cpp.source.includedirs[0], dst="include", keep_path=False)

[memsharded]

Thanks for the feedback.

It seems what you are missing there is a definition of the build folder in layout, something like:

def layout(self):
    self.folders.source = "lib-source"
    self.folders.build = "lib-build"  # Or just "build"
    self.cpp.package.libs = ["mylib"]
    ...

This approach has many advantages, like a clear, fixed and well defined build folder that can be easily .gitignore ignored, simplified command line with less arguments, easier to understand other methods like package(), in which self.build_folder will already use it.

For multi-configuration cases, you can see for example that the cmake_layout() is able to configure a build folder different for different inputs, for example a different build folder for different compilers or architectures or build types. While cmake_layout() can do this automatically and use some other inputs like self.folders.build_folder_vars or the equivalent external conf, doing it for custom layouts is relatively straightforward:

def layout(self):
    self.folders.source = "lib-source"
    self.folders.build = f"lib-build-{self.settings.arch}-{self.settings.build_type}"  # Or just "build"

That way devs will still get different local folders when developing for different settings, without collisions, and the further possible package() logic for flows like conan export-pkg can work way more consistently and robustly.

[memsharded]

Hi @tclarke

Did the last comment help? Any further question or comment? Thanks for the feedback.

[memsharded]

Marking the question as answered, if there is no more activity, it will be closed soon. Thanks!