3.3.1: create temp directory in source tree causes build fail

[kloczek]

After create temp/ directory in source tree I found that build fails.
Looks like some bits are missing in pyproject.toml

Here is test case

+ mkdir temp
+ cd jaraco.classes-3.3.1
+ ASMFLAGS='-m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -O2 -g -grecord-gcc-switches -pipe -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdata-sections -ffunction-sections -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -flto=auto -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -Wall -Werror=format-security'
+ CFLAGS='-m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -O2 -g -grecord-gcc-switches -pipe -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdata-sections -ffunction-sections -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -flto=auto -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -Wall -Werror=format-security'
+ CXXFLAGS='-m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -O2 -g -grecord-gcc-switches -pipe -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdata-sections -ffunction-sections -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -flto=auto -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -Wall -Werror=format-security'
+ FFLAGS='-m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -O2 -g -grecord-gcc-switches -pipe -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdata-sections -ffunction-sections -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -flto=auto -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -Wall -Werror=format-security -I/usr/lib64/gfortran/modules'
+ FCFLAGS='-m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -O2 -g -grecord-gcc-switches -pipe -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdata-sections -ffunction-sections -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -flto=auto -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -Wall -Werror=format-security -I/usr/lib64/gfortran/modules'
+ LDFLAGS='-specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -Wl,--gc-sections -Wl,--as-needed -Wl,--build-id=sha1 -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -Wl,-z,pack-relative-relocs -flto=auto -fuse-linker-plugin'
+ RUSTFLAGS='-C codegen-units=1 -C debuginfo=2 -C opt-level=2 -C link-arg=-Wl,--as-needed -C link-arg=-Wl,--build-id=sha1 -C link-arg=-Wl,-z,now -C link-arg=-specs=/usr/lib/rpm/redhat/redhat-hardened-ld -C link-arg=-Wl,-z,pack-relative-relocs -C link-arg=-Wl,-z,relro -C link-arg=-flto=auto --cap-lints=warn'
+ VALAFLAGS=-g
+ CC=/usr/bin/gcc
+ CXX=/usr/bin/g++
+ FC=/usr/bin/gfortran
+ AR=/usr/bin/gcc-ar
+ NM=/usr/bin/gcc-nm
+ RANLIB=/usr/bin/gcc-ranlib
+ export ASMFLAGS CFLAGS CXXFLAGS FFLAGS FCFLAGS LDFLAGS VALAFLAGS CC CXX FC AR NM RANLIB RUSTFLAGS VALAFLAGS
+ PBR_VERSION=3.3.1
+ PDM_BUILD_SCM_VERSION=3.3.1
+ SETUPTOOLS_SCM_PRETEND_VERSION=3.3.1
+ /usr/bin/python3 -sBm build -w --no-isolation
* Getting build dependencies for wheel...
error: Multiple top-level packages discovered in a flat-layout: ['jaraco', 'temp'].

To avoid accidental inclusion of unwanted files or directories,
setuptools will not proceed with this build.

If you are trying to create a single distribution with multiple packages
on purpose, you should not rely on automatic discovery.
Instead, consider the following options:

1. set up custom discovery (`find` directive with `include` or `exclude`)
2. use a `src-layout`
3. explicitly set `py_modules` or `packages` with a list of names

To find more information, look for "package discovery" on setuptools docs.

ERROR Backend subprocess exited when trying to invoke get_requires_for_build_wheel

[jaraco]

Thanks for the report.

In order to get out of the business of hand-administering the packaging, this project, along with hundreds of others based on jaraco/skeleton have attempted to rely more on the source definition as found in the project in 63535c6 This issue isn't specific to jaraco.classes but would apply to any Setuptools project that's relying on default package discovery, so I'll move it to jaraco/skeleton, but I don't think there's anything the projects should do here. Instead, downstream packagers should consider not creating a "temp" folder or create it with a name that's not a valid Python package name (e.g. .temp or temp+).

Please let me know if there's more background on why you're adding a temp directory and why it has to be in the project folder?

[jaraco]

It may be worth asking Setuptools not to infer directories in the project if they're not in source control or in the manifest.

[kloczek]

Any progress? 🤔
This issue now affects +10 modules.