#@ def call2(a):
nested: #@ a
#@ end

#@ def call1(v):
#@   if True:
#@     call2()
#@   end
#@   return v
#@ end

test1: #@ call1(None)

+++

ERR: 
- function call2 missing 1 argument (a)
    in call2
      stdin:2 | nested: #@ a
    in call1
      stdin:7 | #@     call2()
    in <toplevel>
      stdin:12 | test1: #@ call1(None)