how unequivocally trap errors $etrap intersystems caché?

i've banging conduct lot since this. proceed $etrap (error doing special variable) recognized contingency clever unequivocally trap errors. i've partially successful doing this. nonetheless i'm still blank something, since run user mode (application mode) there internal cache library errors still vulgar application.

what i was:

processx(var)

    set sc=$$processxprotected(var)
    w !,"after slight call"
    quit sc

processxprotected(var)

    new $etrap
    ;this stops cache guess blunder before context. code
    ; resume during line [w !,"after slight call"] above
    set $etrap="set $ecode = """" quit:$quit 0 quit"

    set sc=1 
    set sc=$$processhelper(var)
    quit sc

processhelper(var)

    new $etrap
    ; formula tells cache keep unwindind blunder doing context up
    ; before blunder handling.
    set $etrap="quit:$quit 0 quit"

    anystuff^anyplace(var)

    quit 1

anystufffoo(var)
    ; anything, competence spin servant routines
    ; vicious indicate don't know contexts
    ; combined on. contingency trap errors, any
    ; case.

    ;call middle cache library
    quit

after this, i i way prompt works! nonetheless i cache repository book (application mode, i told) fails aborts way (the blunder trapping apparatus doesn't work expected).