mac “chromedriver” cannot be opened because the developer cannot be verified.

Solution

1. Open terminal
2. Navigate to path where your chromedriver file is located
3. Execute any one of the below commands

Command1: xattr -d com.apple.quarantine <name-of-executable>

Example

/usr/local/Caskroom/chromedriver 
$ xattr -d com.apple.quarantine chromedriver 

(or)

Command2: spctl --add --label 'Approved' <name-of-executable>

Source: https://docwhat.org/upgrading-to-catalina

Note: This will work only with the file(s) where the above command is executed. If a new chromedriver is downloaded then the command has to be executed again on the newly downloaded file