> So shepherd service authors still cannot write blocking code but need
> to yield?

IMO, service should not block service, if they have something important
to do before running a program, why not fork first and do it in the
child-process (maybe wrap the actual startup program in Guile script)?
-- 
Retrieve my PGP public key:

  gpg --recv-keys D47A9C8B2AE3905B563D9135BE42B352A9F6821F

Zihao