Normally, when a field is missing Guix provides a helpful error message
explaining the precise problem:
(define-record-type <t> t make-t t? this-t
(mandatory-field t-mandatory-field))
(t) => t: missing field initializers (mandatory-field) in form (t)
However, if the field is innate, a value is inherited, and the mandatory
field is missing, the error message is not helpful:
(define-record-type <t> t make-t t? this-t
(mandatory-field t-mandatory-field)
(innate-mandatory-field t-innate-mandatory-field (innate))
(define base (t (mandatory-field #t) (innate-mandatory-field #t)))
(t (inherit base)) =>
Backtrace:
12 (primitive-load "/tmp/test.scm")
In ice-9/eval.scm:
721:20 11 (primitive-eval (t (inherit base)))
In ice-9/psyntax.scm:
1229:36 10 (expand-top-sequence (#<syntax:test.scm:6:0 (t #<synt…>) …)
1121:20 9 (parse _ (("placeholder" placeholder)) ((top) #(# # …)) …)
1342:32 8 (syntax-type (t #<syntax:test.scm:6:3 (inherit base)>) # …)
1562:32 7 (expand-macro #<procedure 7f793c5d10e0 at ice-9/eval.s…> …)
In ice-9/eval.scm:
191:35 6 (_ #(#(#<directory (guix-user) 7f7940782a00> #<va…> …) …))
163:9 5 (_ #(#(#<directory (guix-user) 7f7940782a00> #<va…> …) …))
191:35 4 (_ #(#(#(#<directory (guix-user) 7f7940782a00> # …) …) …))
In srfi/srfi-1.scm:
603:19 3 (map2 (innate-mandatory-field mandatory-field) (0 1) 2)
In ice-9/eval.scm:
196:43 2 (_ #(#(#(#<directory (guix-user) 7f7940782a00> # …) …) …))
155:9 1 (_ _)
In ice-9/boot-9.scm:
1685:16 0 (raise-exception _ #:continuable? _)
ice-9/boot-9.scm:1685:16: In procedure raise-exception:
In procedure car: Wrong type argument in position 1 (expecting pair): #f
