GM_log and other GM functions don't work in Greasemonkey scripts
firebug, greasemonkey, logging
Solution
The reason for this is a new special Metadata Block imperative: @grant, added in GM 1.0. If you need GM_log to work, you have to add this line into your script Metadata Block: `"// @grant GM_log"` , otherwise it will not work. You can read about this feature at http://wiki.greasespot.net/@grant.
Problem
I have created a "Hello World" Greasemonkey script in Firefox which contains only one line of code: ``` GM_log("Hello World"); ``` This did not seem to function, at least it did not produce any output in my firebug console. The same with other GM_... functions like GM_wait When I replaced: ``` GM_log("Hello World"); ``` with: ``` alert("Hello World") ``` it worked (so the script headers are not the problem). I have also set the following `about:config` options to true: - `javascript.options.showInConsole` - `extensions.firebug.showChromeErrors` - `extensions.firebug.showChromeMessages` Is there some other setting to change for GM_... functions to work in Greasemonkey scripts? Do I have to change other firebug settings for GM_log messages to show in the firebug console?