1023 - Function requires a header.
Description
    
An attempt was made to invoke a Function without a header, where the given Function requires one.
    
Example
    
Config:
    Alias
{
    .Targets = { 'a', 'b' }
}
Output:
c:\Test\fbuild.bff(2):(1) FASTBuild Error #1023 - Alias() - Function requires a header.
{
^
\--here
Fix:
Alias( 'MyAlias' )
{
    .Targets = { 'a', 'b' }
}
    