When I use the drush site-install command and a form value contains the equal sign (an API key for example), then Drush cuts the value at the equal sign. For example:
drush si -y profile_name --account-name=... --account-pass=... --db-url=mysql:... form_name.field_name="e+gklgfssdk=jgfsfg/11iXP6VJM0MjDpRk2MEKyc="
The value of the form_name.field_name at install will be "e+gklgfssdk", the last characters are missing, Drush cuts the value at the equal sign. This is a bug? Or how can I set the correct value?