pants

#!/usr/bin/env bash
# Copyright 2014 Pants project contributors (see CONTRIBUTORS.md).
# Licensed under the Apache License, Version 2.0 (see LICENSE).

# This bootstrap script runs pants from the live sources in this repo.
#
# The script defaults to running with either Python 3.7 or Python 3.8. To use another Python version,
# prefix the script with `PY=python3.8`.

set -eo pipefail

HERE=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)

# Exposes:
# + determine_python: Determine which interpreter version to use.
# shellcheck source=build-support/common.sh
source "${HERE}/build-support/common.sh"

PY="$(determine_python)"
export PY

# Exposes:
# + activate_pants_venv: Activate a virtualenv for pants requirements, creating it if needed.
# shellcheck source=build-support/pants_venv
source "${HERE}/build-support/pants_venv"

# Exposes:
# + bootstrap_native_code: Builds target-specific native engine binaries.
# shellcheck source=build-support/bin/rust/bootstrap_code.sh
source "${HERE}/build-support/bin/rust/bootstrap_code.sh"

function exec_pants_bare() {
  PANTS_NATIVE_EXE="${HERE}/.pants"
  PANTS_PY_EXE="${HERE}/src/python/pants/bin/pants_loader.py"
  PANTS_SRCPATH="${HERE}/src/python"

  # Redirect activation and native bootstrap to ensure that they don't interfere with stdout.
  activate_pants_venv 1>&2
  bootstrap_native_code 1>&2

  if [ -n "${USE_NATIVE_PANTS}" ]; then
    set +e
    "${PANTS_NATIVE_EXE}" "$@"
    result=$?
    # N.B.: The native pants client currently relies on pantsd being up. If it's not, it will fail
    # with exit code 75 (EX_TEMPFAIL in /usr/include/sysexits.h) and we should fall through to the
    # python pants client which knows how to start up pantsd. This failure takes O(1ms); so has no
    # appreciable impact on --no-pantsd runs.
    if ((result != 75)); then
      exit ${result}
    fi
    set -e
  fi

  # shellcheck disable=SC2086
  PYTHONPATH="${PANTS_SRCPATH}:${PYTHONPATH}" RUNNING_PANTS_FROM_SOURCES=1 \
    exec ${PANTS_PREPEND_ARGS:-} "$(venv_dir)/bin/python" "${PANTS_PY_EXE}" "$@"
}

exec_pants_bare "$@"