Upstream fixed the configure problem, no need to patch.

.SRCINFO

@@ -1,7 +1,7 @@
 pkgbase = hashclash-git
 	pkgdesc = Project HashClash - MD5 & SHA-1 cryptanalysis
-	pkgver = r45.c1159e9
+	pkgver = r46.d833657
-	pkgrel = 3
+	pkgrel = 1
 	url = https://github.com/cr-marcstevens/hashclash
 	arch = x86_64
 	license = MIT
@@ -11,9 +11,7 @@ pkgbase = hashclash-git
 	provides = hashclash
 	conflicts = hashclash
 	source = hashclash::git+https://github.com/cr-marcstevens/hashclash
-	source = cuda.patch
 	md5sums = SKIP
-	md5sums = e50c821804f404ed10ccecc790382f8f
 
 pkgname = hashclash-git
 

PKGBUILD

@@ -1,7 +1,7 @@
 # Maintainer: Bert Peters <bert@bertptrs.nl>
 pkgname=hashclash-git
-pkgver=r45.c1159e9
+pkgver=r46.d833657
-pkgrel=3
+pkgrel=1
 pkgdesc="Project HashClash - MD5 & SHA-1 cryptanalysis "
 arch=(x86_64)
 url="https://github.com/cr-marcstevens/hashclash"
@@ -10,18 +10,8 @@ depends=(boost-libs)
 makedepends=('git' 'boost')
 provides=("${pkgname%-git}")
 conflicts=("${pkgname%-git}")
-source=("${pkgname%-git}::git+https://github.com/cr-marcstevens/hashclash"
+source=("${pkgname%-git}::git+https://github.com/cr-marcstevens/hashclash")
-		"cuda.patch")
+md5sums=('SKIP')
-md5sums=('SKIP'
-         'e50c821804f404ed10ccecc790382f8f')
-
-# Please refer to the 'USING VCS SOURCES' section of the PKGBUILD man page for
-# a description of each element in the source array.
-
-prepare() {
-	cd "$srcdir/${pkgname%-git}"
-	patch -p1 < "$srcdir/cuda.patch"
-}
 
 pkgver() {
 	cd "$srcdir/${pkgname%-git}"

cuda.patch

@@ -1,32 +0,0 @@
-diff --git a/m4/ax_cuda.m4 b/m4/ax_cuda.m4
-index f9d9f8e..82646b0 100644
---- a/m4/ax_cuda.m4
-+++ b/m4/ax_cuda.m4
-@@ -88,17 +88,9 @@ then
- 	# test if nvcc version is >= 2.3
- 	NVCC_VERSION=`$NVCC --version | grep release | awk 'gsub(/,/, "") {print [$]5}'`
- 	AC_MSG_RESULT([nvcc version : $NVCC_VERSION])
--	
-+
- 	# test if architecture is 64 bits and NVCC version >= 2.3
-         libdir=lib
--        AX_COMPARE_VERSION([$NVCC_VERSION],[gt],[2.2],[
--	    if test "x$host_cpu" = xx86_64 ; then
--	        libdir=lib64
--	    fi
--	    if test "x$host_cpu" = xpowerpc64le ; then
--	        libdir=lib64
--	    fi
--	])
- 
- 	# set CUDA flags
- 	if test -n "$cuda_home_path"
-@@ -163,7 +155,7 @@ then
- 
- 	CPPFLAGS=$saved_CPPFLAGS
- 	LIBS=$saved_LIBS
--fi	
-+fi
- 
- have_cuda="no"
- if test "$want_cuda" != "no" -a "$have_cuda_headers" = "yes" -a "$have_cuda_libs" = "yes" -a "$have_nvcc" = "yes"