+ case $bool in
+ true) return 0 ;;
+ false) return 1 ;;
+ '')
+ lf-echo-stderr "ERROR: ${FUNCNAME[0]}() line:{BASH_LINENO[0]} : A boolean cannot be a empty string" >&2
+ return 2
+ ;;
+ *)
+ lf-echo-stderr "ERROR: ${FUNCNAME[0]}() line: ${BASH_LINENO[0]} : Invalid value for a boolean: '$bool'"
+ return 2
+ ;;
+ esac
+}
+
+################################################################################
+#
+# NAME
+# lf-activate-venv [-p|--python python] [--no-path]
+# [--system-site-packages] [package]...
+#
+# SYNOPSIS
+# # shellcheck disable=SC1090
+# source ~/lf-env.sh
+#
+# lf-activate-venv tox tox-pyenv
+# or
+# lf-activate-venv jenkins-job-builder
+# or
+# lf-activate-venv lftools
+# or
+# lf-activate-venv --python 3.6 git-review
+#
+# DESCRIPTION
+# This function will create a new Python Virtual Environment (venv) and
+# install the specified packages in the new venv. The venv will be installed
+# in $lf_venv and by default, the $lf_venv/bin directory will be prepended
+# to the PATH.
+#
+# The 'lf_venv' variable will be set so you can directly execute commands
+# in the venv with: $lf_venv/bin/command. Beware that subsequent calls to
+# lf-activate-venv() will overwrite 'lf_venv'.
+#
+# By default all packages are installed with '--upgrade-strategy eager'.
+# The venv will always contain pip & virtualenv.
+#
+# Some packages have a default version. If one of those packages is specified,
+# the 'version' specifier will be added for the install. If the version is
+# specified on the command line that version will be used.
+# The following packages have default versions:
+# Package Version
+# jenkins-job-builder $JJB_VERSION
+#
+# If the --python flag is specified, the specified python executable will be
+# used to create the venv. The --python option must be in the PATH. The venv
+# will be located in $lf_venv (/tmp/venv-####).
+#
+# If the --no-path flag is specified, $lf_venv/bin will not be prepended to
+# the PATH.
+#
+# If the --system-site-packages flag is specified, the --system-site-packages
+# flag will be passed to the inital 'pip install' (python3* only).
+#
+# RETURN VALUES
+# OK: 0
+# Fail: 1
+#
+################################################################################
+
+function lf-activate-venv()
+{
+ lf_venv=$(mktemp -d /tmp/venv-XXXX)
+ local python=python3
+ local options
+ local set_path=true
+ local install_args=""
+ options=$(getopt -o 'n:p:' -l 'no-path,python:,system-site-packages' -n "${FUNCNAME[0]}" -- "$@" )
+ eval set -- "$options"
+ while true; do
+ case $1 in
+ -n|--no-path) set_path=false ; shift ;;
+ -p|--python) python=$2 ; shift 2 ;;
+ --system-site-packages) install_args="--system-site-packages" ; shift ;;
+ --) shift; break ;;
+ *) lf-echo-stderr "${FUNCNAME[0]}(): ERROR: Unknown switch '$1'." ; return 1 ;;
+ esac
+ done
+ if ! type $python > /dev/null; then
+ lf-echo-stderr "${FUNCNAME[0]}(): ERROR: Unknown Python: $python"
+ return 1