INFO: setup
Package:    dev-vcs/mercurial-6.8:0
Repository: gentoo
Maintainer: cedk@gentoo.org
USE:        abi_x86_64 amd64 chg elibc_glibc kernel_linux python_targets_python3_10 python_targets_python3_11 python_targets_python3_12
FEATURES:   preserve-libs sandbox userpriv usersandbox
INFO: prepare
Build system packages:
  dev-python/gpep517            : 15
  dev-python/installer          : 0.7.0
  dev-python/cython             : 3.0.9
  dev-python/setuptools         : 72.1.0
  dev-python/setuptools-rust    : 1.9.0
  dev-python/setuptools-scm     : 8.1.0
  dev-python/wheel              : 0.44.0
INFO: compile
python3_10: running distutils-r1_run_phase python_compile
  Building the wheel for mercurial-6.8 via setuptools.build_meta:__legacy__
ERROR: compile
ERROR: dev-vcs/mercurial-6.8::gentoo failed (compile phase):
  FATAL: please call cargo_gen_config before using cargo_env

Call stack:
    ebuild.sh, line  136:  Called src_compile
  environment, line 4763:  Called distutils-r1_src_compile
  environment, line 2212:  Called _distutils-r1_run_foreach_impl 'python_compile'
  environment, line  853:  Called python_foreach_impl 'distutils-r1_run_phase' 'python_compile'
  environment, line 4193:  Called multibuild_foreach_variant '_python_multibuild_wrapper' 'distutils-r1_run_phase' 'python_compile'
  environment, line 3703:  Called _multibuild_run '_python_multibuild_wrapper' 'distutils-r1_run_phase' 'python_compile'
  environment, line 3701:  Called _python_multibuild_wrapper 'distutils-r1_run_phase' 'python_compile'
  environment, line 1288:  Called distutils-r1_run_phase 'python_compile'
  environment, line 2196:  Called python_compile
  environment, line 3975:  Called distutils-r1_python_compile 'build_ext'
  environment, line 2018:  Called distutils_pep517_install '/var/tmp/portage/dev-vcs/mercurial-6.8/work/mercurial-6.8-python3_10/install'
  environment, line 2541:  Called cargo_env 'python3.10' '-m' 'gpep517' 'build-wheel' '--prefix=/usr' '--backend' 'setuptools.build_meta:__legacy__' '--output-fd' '3' '--wheel-dir' '/var/tmp/portage/dev-vcs/mercurial-6.8/work/mercurial-6.8-python3_10/wheel'
  environment, line 1773:  Called die
The specific snippet of code:
      [[ -n ${_CARGO_GEN_CONFIG_HAS_RUN} ]] || die "FATAL: please call cargo_gen_config before using ${FUNCNAME}";

If you need support, post the output of `emerge --info '=dev-vcs/mercurial-6.8::gentoo'`,
the complete build log and the output of `emerge -pqv '=dev-vcs/mercurial-6.8::gentoo'`.
The complete build log is located at '/var/cache/portage/logs/build/dev-vcs/mercurial-6.8:20240808-145221.log'.
For convenience, a symlink to the build log is located at '/var/tmp/portage/dev-vcs/mercurial-6.8/temp/build.log'.
The ebuild environment file is located at '/var/tmp/portage/dev-vcs/mercurial-6.8/temp/environment'.
Working directory: '/var/tmp/portage/dev-vcs/mercurial-6.8/work/mercurial-6.8'
S: '/var/tmp/portage/dev-vcs/mercurial-6.8/work/mercurial-6.8'