bug#36667: crates-io.scm packages should build on master

[goodoldpaul@autistici.org]

[-- Attachment #1: Type: text/plain, Size: 413 bytes --]

Rust libraries contained in gnu/packages/crates-io.scm are not building 
anymore because cargo wants to download crate dependencies inside the 
store.

The attached patch sets the CARGO_HOME environment variable  to "." much 
earlier than it previously was, just after the configure phase. With the 
attached patch all packages in crates-io.scm build without errors.

I hope I did everything right,

Bye,

Giacomo

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-guix-Fix-cargo-build-system.patch --]
[-- Type: text/x-diff; name=0001-guix-Fix-cargo-build-system.patch, Size: 1473 bytes --]

From 867b8bd5fc43305b3dac3d9c8e7574344170d8aa Mon Sep 17 00:00:00 2001
From: Giacomo Leidi <goodoldpaul@autistici.org>
Date: Mon, 15 Jul 2019 16:07:00 +0200
Subject: [PATCH] guix: Fix cargo-build-system.

* guix/build/cargo-build-system.scm (install): Moved CARGO_HOME setting
to...
* guix/build/cargo-build-system.scm (configure): ... here.
---
 guix/build/cargo-build-system.scm | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/guix/build/cargo-build-system.scm b/guix/build/cargo-build-system.scm
index 1f36304b15..a34bd0632a 100644
--- a/guix/build/cargo-build-system.scm
+++ b/guix/build/cargo-build-system.scm
@@ -118,6 +118,9 @@ directory = '" port)
   ;; upgrading the compiler for example.
   (setenv "RUSTFLAGS" "--cap-lints allow")
   (setenv "CC" (string-append (assoc-ref inputs "gcc") "/bin/gcc"))
+  ;; Force cargo to honor our .cargo/config definitions
+  ;; https://github.com/rust-lang/cargo/issues/6397
+  (setenv "CARGO_HOME" ".")
   #t)
 
 (define* (build #:key
@@ -148,9 +151,6 @@ directory = '" port)
     ;; Make cargo reuse all the artifacts we just built instead
     ;; of defaulting to making a new temp directory
     (setenv "CARGO_TARGET_DIR" "./target")
-    ;; Force cargo to honor our .cargo/config definitions
-    ;; https://github.com/rust-lang/cargo/issues/6397
-    (setenv "CARGO_HOME" ".")
 
     ;; Only install crates which include binary targets,
     ;; otherwise cargo will raise an error.
-- 
2.22.0