File not found error while executing gunicorn command

Below is our gradle setup

```
buildscript {
dependencies {
classpath group: 'com.linkedin.pygradle', name: 'pygradle-plugin', version: '0.12.10'
}
}
apply plugin: 'com.linkedin.python-web-app'

python {
testDir = file('tests')
srcDir = file('src/main/python')
forceVersion("pypi:flake8:3.2.1")
if (project.hasProperty("PYTHON_VERSION")) {
details.pythonVersion = project.get("PYTHON_VERSION")
}
if (project.hasProperty("PYTHON_PATH")) {
details.systemPythonInterpreter = project.get("PYTHON_PATH")
}

}

```

We have a Jenkins server that has default python 2.7. We have installed additional python plugin 3.7 but it is not Jenkins server default.

We set the systemPythonInterpreter and pythonVersion values correctly to version 3.7. When we run the gunicorn command this fails with

`/usr/bin/env: /opt/path/bin/microservice_appl.pex: No such file or directory`

When we build on a local windows machine with only python version 3.7 installed a gunicorn.py file is correctly built and the installation works fine.

Start by reproducing the gunicorn command from the provided Gradle configuration on Jenkins, checking the configured Python 3.7 interpreter and the generated /opt/path/bin/microservice_appl.pex path. Done means the command resolves the executable and runs successfully under the non-default Python installation; compare with the working Windows build.

Written by the indexing model from the issue text.