Keep failure status of any build step
 

And make it available through macro,
e.g.: %FAIL_STATUS("mystepname")%

This idea I like, although there are a number of issues:

1/ there may be more than one step with the same name,
2/ the step may be nested in a subroutine call sequence so the context would be required as well,
3/ should there be an entry for each itteration through a repeated group of steps?

all those three cases are generic and can be resolved by some complex syntax:

1/ full path to step (e.g. "buidproject\copyfiles\copy_exe", if omitted use ANY step with specified name (name clash is up to user).
2/ include opional context information as well (e.g. "buidproject\copyfiles\copy_exe:mysubrootine\mysubs tep"),
3/ my imagination is exhausted :) need to invent even more complex syntax...

You can get a basic implementation of this by calling a common function in each step's vbld_StepDone event which stores that step's status in a temporary macro named for the step. To update several steps to do this, you can multi-select the steps and edit the step script code to call a common function (StoreStepStatus [defined as a project script function] in the sample). A VBScript sample is attached.