contrib: guix: Various improvements.

- Clearer and more accurate prose
- Pin `guix pull' to commit rather than branch
- Just use `use-module' instead of `define-module'
- Use `bash-minimal' instead of `bash'
- Remove unneeded `tcsh' from manifest
- Explicitly use `python-3.7'
- Add comments about how {native,cross}-toolchains are produced and
  why

contrib/guix/README.md

@@ -15,7 +15,8 @@ Conservatively, a x86_64 machine with:
 
 - 2 or more logical cores
 - 4GB of free disk space on the partition that /gnu/store will reside in
-- 24GB of free disk space on the partition that the bitcoin repository resides in
+- 24GB of free disk space on the partition that the Bitcoin Core git repository
+  resides in
 
 > Note: these requirements are slightly less onerous than those of Gitian builds
 
@@ -43,7 +44,7 @@ profile. The changes there are slowly being upstreamed.
 
 ```sh
 guix pull --url=https://github.com/dongcarl/guix.git \
-          --branch=2019-05-bitcoin-staging \
+          --commit=82c77e52b8b46e0a3aad2cb12307c2e30547deec \
           --max-jobs=4 # change accordingly
 ```
 

contrib/guix/guix-build.sh

@@ -19,8 +19,8 @@ for host in ${HOSTS=i686-linux-gnu x86_64-linux-gnu arm-linux-gnueabihf aarch64-
     # Display proper warning when the user interrupts the build
     trap 'echo "** INT received while building ${host}, you may want to clean up the relevant output and distsrc-* directories before rebuilding"' INT
 
-    # Run the build script 'contrib/guix/build.sh' in the build container
-    # specified by 'contrib/guix/manifest.scm'
+    # Run the build script 'contrib/guix/libexec/build.sh' in the build
+    # container specified by 'contrib/guix/manifest.scm'
     # shellcheck disable=SC2086
     guix environment --manifest="${PWD}/contrib/guix/manifest.scm" \
                      --container \

contrib/guix/manifest.scm

@@ -1,26 +1,25 @@
-(define-module (bitcoin)
-  #:use-module (gnu)
-  #:use-module (gnu packages)
-  #:use-module (gnu packages autotools)
-  #:use-module (gnu packages base)
-  #:use-module (gnu packages bash)
-  #:use-module (gnu packages check)
-  #:use-module (gnu packages commencement)
-  #:use-module (gnu packages compression)
-  #:use-module (gnu packages cross-base)
-  #:use-module (gnu packages file)
-  #:use-module (gnu packages gawk)
-  #:use-module (gnu packages gcc)
-  #:use-module (gnu packages linux)
-  #:use-module (gnu packages perl)
-  #:use-module (gnu packages pkg-config)
-  #:use-module (gnu packages python)
-  #:use-module (gnu packages shells)
-  #:use-module (guix build-system trivial)
-  #:use-module (guix gexp)
-  #:use-module (guix packages)
-  #:use-module (guix profiles)
-  #:use-module (guix utils))
+(use-modules (gnu)
+             (gnu packages)
+             (gnu packages autotools)
+             (gnu packages base)
+             (gnu packages bash)
+             (gnu packages check)
+             (gnu packages commencement)
+             (gnu packages compression)
+             (gnu packages cross-base)
+             (gnu packages file)
+             (gnu packages gawk)
+             (gnu packages gcc)
+             (gnu packages linux)
+             (gnu packages perl)
+             (gnu packages pkg-config)
+             (gnu packages python)
+             (gnu packages shells)
+             (guix build-system trivial)
+             (guix gexp)
+             (guix packages)
+             (guix profiles)
+             (guix utils))
 
 (define (make-ssp-fixed-gcc xgcc)
   "Given a XGCC package, return a modified package that uses the SSP function
@@ -101,7 +100,7 @@ chain for " target " development."))
       (license (package-license xgcc)))))
 
 (define* (make-bitcoin-cross-toolchain target
-                                  #:optional
+                                  #:key
                                   (base-gcc-for-libc gcc-5)
                                   (base-kernel-headers linux-libre-headers-4.19)
                                   (base-libc glibc-2.27)
@@ -117,8 +116,7 @@ desirable for building Bitcoin Core release binaries."
 
 (packages->manifest
  (list ;; The Basics
-       bash
-       tcsh
+       bash-minimal
        which
        coreutils
        util-linux
@@ -145,11 +143,16 @@ desirable for building Bitcoin Core release binaries."
        pkg-config
        ;; Scripting
        perl
-       python
-       ;; Toolchains
+       python-3.7
+       ;; Native gcc 9 toolchain targeting glibc 2.27
        (make-gcc-toolchain gcc-9 glibc-2.27)
-       (make-bitcoin-cross-toolchain "riscv64-linux-gnu" gcc-8)
-       (make-bitcoin-cross-toolchain "x86_64-linux-gnu")
+       ;; Cross gcc 9 toolchains targeting glibc 2.27
        (make-bitcoin-cross-toolchain "i686-linux-gnu")
+       (make-bitcoin-cross-toolchain "x86_64-linux-gnu")
        (make-bitcoin-cross-toolchain "aarch64-linux-gnu")
-       (make-bitcoin-cross-toolchain "arm-linux-gnueabihf" gcc-6)))
+       (make-bitcoin-cross-toolchain "arm-linux-gnueabihf")
+       ;; The glibc 2.27 for riscv64 needs gcc 7 to successfully build (see:
+       ;; https://www.gnu.org/software/gcc/gcc-7/changes.html#riscv). The final
+       ;; toolchain is still a gcc 9 toolchain targeting glibc 2.27.
+       (make-bitcoin-cross-toolchain "riscv64-linux-gnu"
+                                     #:base-gcc-for-libc gcc-7)))