JJ: Description from the destination commit:

setup_cmd: add --output-pubkey

JJ: Description from source commit:
use cmdliner

tools/recfile_parser.ml

@@ -0,0 +1,51 @@
+(* very rudimentary recfile parser
+   https://www.gnu.org/software/recutils/manual/recutils.html#The-Rec-Format *)
+
+open Angstrom
+
+type field = {
+  k: string;
+  v: string;
+}
+
+type record = field list
+
+let newline = char '\n'
+let is_newline = function '\n' -> true | _ -> false
+
+let field_name =
+  let first_char =
+    satisfy (function 'a' .. 'z' | 'A' .. 'Z' | '%' -> true | _ -> false)
+  in
+  let subsequent_char =
+    satisfy (function
+      | 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' -> true
+      | _ -> false)
+  in
+  lift2
+    (fun hd tl -> String.of_seq (List.to_seq (hd :: tl)))
+    first_char (many subsequent_char)
+
+(* todo handle '\' escape and '+' on next line *)
+let field_value = take_till is_newline <* newline
+
+let field =
+  let blank = satisfy (function ' ' | '\t' -> true | _ -> false) in
+  let blanks = skip_many1 blank in
+  lift3 (fun k () v -> { k; v }) field_name (char ':' *> blanks) field_value
+
+let blank = newline *> return ()
+let comment = (char '#' *> take_till is_newline <* newline) *> return ()
+let record = many1 field
+
+let records =
+  let sep =
+    (* at least one blank line *)
+    skip_many comment *> blank *> skip_many (comment <|> blank)
+  in
+  sep_by1 sep record
+
+let recfile : record list t =
+  skip_many (comment <|> blank) *> records <* skip_many (comment <|> blank)
+
+let parse s = parse_string ~consume:All recfile s