[question] source_folder and build_folder are empty inside generate method

[pasrom]

The self.source_folder and self.build_folder are empty inside the generate method when doing a conan install. While conan create works as I would expect it. I'm using conan version 1.45.0.

Is this desired behavior?

Using following conanfile:

from conans import ConanFile

class Test(ConanFile):
    version = "1.2.3"
    name = "test"

    def generate(self):
        self.output.info("generate sf: {}".format(self.source_folder))
        self.output.info("generate bf: {}".format(self.build_folder))

Output conan install

Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++
compiler.version=10
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

conanfile.py (test/1.2.3): Installing package
Requirements
Packages

Installing (downloading, building) binaries...
conanfile.py (test/1.2.3): Generator txt created conanbuildinfo.txt
conanfile.py (test/1.2.3): Calling generate()
conanfile.py (test/1.2.3): generate sf: None
conanfile.py (test/1.2.3): generate bf: None
conanfile.py (test/1.2.3): Aggregating env generators
conanfile.py (test/1.2.3): Generated conaninfo.txt
conanfile.py (test/1.2.3): Generated graphinfo

Output conan create

Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++
compiler.version=10
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

conanfile.py (test/1.2.3): Installing package
Requirements
Packages

Installing (downloading, building) binaries...
conanfile.py (test/1.2.3): Generator txt created conanbuildinfo.txt
conanfile.py (test/1.2.3): Calling generate()
conanfile.py (test/1.2.3): generate sf: None
conanfile.py (test/1.2.3): generate sf: None
conanfile.py (test/1.2.3): Aggregating env generators
conanfile.py (test/1.2.3): Generated conaninfo.txt
conanfile.py (test/1.2.3): Generated graphinfo
jenkins@1f05df87e5a4:~/ws/conan-semver/package-a/build$ conan create .. 
[HOOK - attribute_checker.py] pre_export(): WARN: Conanfile doesn't have 'url'. It is recommended to add it as attribute
[HOOK - attribute_checker.py] pre_export(): WARN: Conanfile doesn't have 'license'. It is recommended to add it as attribute
[HOOK - attribute_checker.py] pre_export(): WARN: Conanfile doesn't have 'description'. It is recommended to add it as attribute
Exporting package recipe
test/1.2.3: A new conanfile.py version was exported
test/1.2.3: Folder: /home/jenkins/.conan/data/test/1.2.3/_/_/export
test/1.2.3: Using the exported files summary hash as the recipe revision: fb4654606f8a8663d725d4ffb122acfa 
test/1.2.3: Package recipe modified in export, forcing source folder removal
test/1.2.3: Use the --keep-source, -k option to skip it
test/1.2.3: Removing the local binary packages from different recipe revisions
test/1.2.3: Exported revision: fb4654606f8a8663d725d4ffb122acfa
Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++
compiler.version=10
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

test/1.2.3: Forced build from source
Installing package: test/1.2.3
Requirements
    test/1.2.3 from local cache - Cache
Packages
    test/1.2.3:5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9 - Build

Installing (downloading, building) binaries...
test/1.2.3: Configuring sources in /home/jenkins/.conan/data/test/1.2.3/_/_/source
test/1.2.3: Copying sources to build folder
test/1.2.3: Building your package in /home/jenkins/.conan/data/test/1.2.3/_/_/build/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
test/1.2.3: Generator txt created conanbuildinfo.txt
test/1.2.3: Calling generate()
test/1.2.3: generate sf: /home/jenkins/.conan/data/test/1.2.3/_/_/build/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
test/1.2.3: generate bf: /home/jenkins/.conan/data/test/1.2.3/_/_/build/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
test/1.2.3: Aggregating env generators
test/1.2.3: Calling build()
test/1.2.3: WARN: This conanfile has no build step
test/1.2.3: Package '5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9' built
test/1.2.3: Build folder /home/jenkins/.conan/data/test/1.2.3/_/_/build/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
test/1.2.3: Generated conaninfo.txt
test/1.2.3: Generated conanbuildinfo.txt
test/1.2.3: Generating the package
test/1.2.3: Package folder /home/jenkins/.conan/data/test/1.2.3/_/_/package/5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
test/1.2.3: Calling package()
test/1.2.3: WARN: This conanfile has no package step
test/1.2.3 package(): WARN: No files in this package!
test/1.2.3: Package '5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9' created
test/1.2.3: Created package revision 8b2b6f3200edc3d5cdc4faf769914f3b

[memsharded]

Hi @pasrom

You would need to define the layout() method. Something like:

 def layout(self):
      self.folders.source = "."
      self.folders.build = "build"

It also had a bug, only the source folder was being computed, so I have submitted #10567 to fixe build_folder for next release 1.46. Thanks for reporting!

[pasrom]

Thank you for your quick response.

[memsharded]

#10567 merged, this will be in 1.46