I got my set of robot framework tests, that works correctly on my localhost.
The geckodriver is located in project folder as
Project_name/webdrivers/geckodriver.exe
Then I have this keyword set as Test Setup:
Set Environment Variable webdriver.gecko.driver Project_name/webdrivers/geckodriver.exe
This however doesn't work when run tests via Team City, and I got this message:
WebDriverException: Message: 'geckodriver' executable needs to be in PATH
This should be easily solved by a google search for "add program to path"
export PATH=$PATH:/path/to/geckodriver
You can expand the path for a build agent by adding a build parameter named "env.PATH" with the following value on Mac OS and Linux.
%env.PATH%:/my/path
On Windows use ";" instead of ":" as the path delimiter.
You can also add the following to conf/buildAgent.properties in your build agent installation directory.
env.PATH=%env.PATH%:/my/path