[bug#37870] [PATCH v2] gnu: make-nsis: Fix cross-compilation.

[Carl Dong]

Updated the patch to make it look a little better :-)
Will push to master tomorrow if no objections.

-----

* gnu/packages/installers.scm (make-nsis)[arguments]: Enforce correct
ordering of search paths (mingw-w64 last).
---
 gnu/packages/installers.scm | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/installers.scm b/gnu/packages/installers.scm
index c987254d61..035d38ac5a 100644
--- a/gnu/packages/installers.scm
+++ b/gnu/packages/installers.scm
@@ -48,6 +48,7 @@
       (arguments
        `(#:scons ,scons-python2
          #:modules ((srfi srfi-1)
+                    (srfi srfi-26)
                     (guix build utils)
                     (guix build scons-build-system))
          #:tests? #f
@@ -92,7 +93,19 @@
                              ;; CROSS_-prefixed version of env vars
                              (setenv (string-append "CROSS_" env-name)
                                      (filter-delimited-string env-val 
mingw-path?))))
-                         '("CPLUS_INCLUDE_PATH" "LIBRARY_PATH" 
"C_INCLUDE_PATH"))))
+                         '("CPATH" "LIBRARY_PATH"))
+                        ;; Hack to place mingw-w64 path at the end of search
+                        ;; paths.  Could probably use a specfile and dirafter
+                        (setenv "CROSS_CPLUS_INCLUDE_PATH"
+                                (string-join
+                                 `(,@(map (cut string-append (assoc-ref 
%build-inputs "xgcc") <>)
+                                          `("/include/c++"
+                                            ,(string-append "/include/c++/" 
,triplet)
+                                            "/include/c++/backward"
+                                            
"/lib/gcc/x86_64-w64-mingw32/7.4.0/include"
+                                            
"/lib/gcc/x86_64-w64-mingw32/7.4.0/include-fixed"))
+                                   ,(getenv "CROSS_CPATH"))
+                                 ":"))))
                     (add-before 'build 'fix-target-detection
                       (lambda _
                         ;; NSIS target detection is screwed up, manually
--
2.23.0