gnu: julia-tracker: Patch for julia-1.6.

* gnu/packages/julia-xyz.scm (julia-tracker)[source]: Add patch.
* gnu/packages/patches/julia-tracker-16-compat.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu/local.mk

@@ -1289,6 +1289,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/jfsutils-include-systypes.patch		\
   %D%/packages/patches/jsoncpp-fix-inverted-case.patch		\
   %D%/packages/patches/julia-SOURCE_DATE_EPOCH-mtime.patch	\
+  %D%/packages/patches/julia-tracker-16-compat.patch		\
   %D%/packages/patches/kdbusaddons-kinit-file-name.patch	\
   %D%/packages/patches/libblockdev-glib-compat.patch		\
   %D%/packages/patches/libffi-3.3-powerpc-fixes.patch		\

gnu/packages/julia-xyz.scm

@@ -21,6 +21,7 @@
 
 (define-module (gnu packages julia-xyz)
   #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (gnu packages)
   #:use-module (guix packages)
   #:use-module (guix git-download)
   #:use-module (guix build-system julia)
@@ -3938,7 +3939,8 @@ package.")
                (commit (string-append "v" version))))
         (file-name (git-file-name name version))
         (sha256
-         (base32 "1s4mdywbp7nli7z985fqaj1rs4i6d92b1jx3lhg0qhk1s5wc0v8j"))))
+         (base32 "1s4mdywbp7nli7z985fqaj1rs4i6d92b1jx3lhg0qhk1s5wc0v8j"))
+        (patches (search-patches "julia-tracker-16-compat.patch"))))
     (build-system julia-build-system)
     (propagated-inputs
      `(("julia-adapt" ,julia-adapt)

gnu/packages/patches/julia-tracker-16-compat.patch

@@ -0,0 +1,40 @@
+https://github.com/FluxML/Tracker.jl/commit/f6550ba38a9ea5802e2de4fa9c939929ba711f0d.patch
+from an upstream pull request
+https://github.com/FluxML/Tracker.jl/pull/94
+
+
+From f6550ba38a9ea5802e2de4fa9c939929ba711f0d Mon Sep 17 00:00:00 2001
+From: Michael Abbott <me@escbook>
+Date: Wed, 3 Feb 2021 22:58:33 +0100
+Subject: [PATCH] two fixes for 1.6
+
+---
+ src/lib/array.jl | 2 +-
+ src/lib/real.jl  | 1 +
+ 2 files changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/lib/array.jl b/src/lib/array.jl
+index 92f2b39..f8cbbac 100644
+--- a/src/lib/array.jl
++++ b/src/lib/array.jl
+@@ -298,7 +298,7 @@ Base.reverse(xs::TrackedArray; dims) = track(reverse, xs, dims = dims)
+ @grad reverse(xs; dims) = reverse(data(xs), dims = dims), Δ -> (reverse(Δ, dims = dims), nothing)
+ Base.reverse(xs::TrackedVector) = track(reverse, xs)
+ @grad reverse(xs::TrackedVector) = reverse(data(xs)), Δ -> (reverse(Δ),)
+-Base.reverse(xs::TrackedVector, start, stop) = track(reverse, xs, start, stop)
++Base.reverse(xs::TrackedVector, start::Integer, stop::Integer) = track(reverse, xs, start, stop)
+ @grad reverse(xs, start, stop) = reverse(data(xs), start, stop), Δ -> (reverse(Δ, start, stop), nothing, nothing)
+ 
+ function _kron(mat1::AbstractMatrix,mat2::AbstractMatrix)
+diff --git a/src/lib/real.jl b/src/lib/real.jl
+index 737afd8..e1975ac 100644
+--- a/src/lib/real.jl
++++ b/src/lib/real.jl
+@@ -55,6 +55,7 @@ for f in :[isinf, isnan, isfinite].args
+ end
+ 
+ Printf.fix_dec(x::TrackedReal, n::Int, a...) = Printf.fix_dec(data(x), n, a...)
++Printf.tofloat(x::TrackedReal) = Printf.tofloat(data(x))
+ 
+ Base.float(x::TrackedReal) = x
+