Ludovic Courtès writes:
>> From 56f43a9042853aca79f60808a51d328dfbe420a3 Mon Sep 17 00:00:00 2001
>> From: Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>
>> Date: Tue, 23 Dec 2014 12:31:50 +0100
>> Subject: [PATCH] gnu: Add GCJ
>>
>> * gnu/packages/gcc.scm (gcj-4.8, ecj-bootstrap-4.8): New variable.
>> * gnu/packages/javac.in: New file.
>
> You need something like this in gnu-system.am:
>
>   MISC_DISTRO_FILES = gnu/packages/javac.in
>
> and in Makefile.am, change the nobase_dist_guilemodule_DATA line to:
>
>   nobase_dist_guilemodule_DATA =       \
>     $(MODULES) $(KCONFIGS) $(EXAMPLES) \
>     $(MISC_DISTRO_FILES)
>
>> +    (inputs
>> +     (append (package-inputs gcc-4.8)
>> +             `(("fastjar"       ,fastjar)
>> +               ("perl"          ,perl)
>> +               ("javac.in"      ,(search-path %load-path
>> +                                              "gnu/packages/javac.in"))
>> +               ("ecj-bootstrap" ,ecj-bootstrap-4.8))))
>
> Minor issue: I would avoid comma alignment and use quasiquote +
> unquote-splicing rather than ‘append’.
>
>> +(define-public ecj-bootstrap-4.8
>> +  (package
>> +    (name "ecj-bootstrap")
>> +    (version "4.8")
>> +    (source (origin
>> +              (method url-fetch)
>> +              (uri (string-append "ftp://sourceware.org/pub/java/ecj-" version ".jar"))
>> +              (sha256
>> +               (base32
>> +                "10fpqfbdzff1zcbxzh66xc8xbij9saykcj4xzm19wk9p3n7i5zcq"))))
>
> It’s enough to make it an ‘origin’, and to keep it private:
>
>   (define ecj-bootstrap-4.8
>     (origin
>       (method ...)
>       ...))

Attached is a new patch that incorporates all of your suggestions.

~~ Ricardo