Error running new project-config/rebuild command

[benface]

Description

I'm trying to use the new project-config/rebuild CLI command and getting this error:

Rebuilding the project config from the current state ... error: Argument 1 passed to craft\helpers\Json::decodeIfJson() must be of the type string, null given, called in .../vendor/craftcms/cms/src/services/ProjectConfig.php on line 1607

Additional info

• Craft version: 3.1.20
• PHP version: PHP 7.1.23
• Database driver & version: MySQL 5.7.25

[brandonkelly]

Fixed for the next release.

To get the fix early, change your craftcms/cms requirement in composer.json to:

"require": {
  "craftcms/cms": "dev-develop#5713b9ec4865fb058ab46ac4c062e152cd737e99 as 3.1.20",
  "...": "..."
}

Then run composer update.

[brandonkelly]

Just released 3.1.20.1 with this fix.