Index: libraries/source/nvtt/README.txt
===================================================================
--- libraries/source/nvtt/README.txt
+++ libraries/source/nvtt/README.txt
@@ -4,6 +4,8 @@
   cmake-freebsd.patch (fixes build on FreeBSD)
   issue188.patch (fixes http://code.google.com/p/nvidia-texture-tools/issues/detail?id=188)
   issue261.patch (fixes https://github.com/castano/nvidia-texture-tools/issues/261)
+  pr270.patch (from https://github.com/castano/nvidia-texture-tools/pull/270)
   rpath.patch (fixes .so file search paths for bundled copy)
   win-shared-build.patch (adapted from https://github.com/castano/nvidia-texture-tools/pull/285)
   musl-build.patch (fixes build on musl linux; contributed by voroskoi, with a part by leper, see https://code.wildfiregames.com/D2491)
+  arm-build.patch (fixes build on non-aarch64 arm, TODO send upstream after Stan tests it)
Index: libraries/source/nvtt/patches/arm-build.patch
===================================================================
--- /dev/null
+++ libraries/source/nvtt/patches/arm-build.patch
@@ -0,0 +1,28 @@
+---
+ src/nvcore/Debug.cpp | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/src/nvcore/Debug.cpp b/src/nvcore/Debug.cpp
+index 7379971..f96b937 100644
+--- a/src/nvcore/Debug.cpp
++++ b/src/nvcore/Debug.cpp
+@@ -665,6 +665,9 @@ namespace
+ #  elif NV_CPU_PPC
+         ucontext_t * ucp = (ucontext_t *)secret;
+         return (void *) ucp->uc_mcontext.regs->nip;
++#    elif NV_CPU_ARM
++        ucontext_t * ucp = (ucontext_t *)secret;
++        return (void *) ucp->uc_mcontext.arm_pc;
+ #    elif NV_CPU_AARCH64
+         ucontext_t * ucp = (ucontext_t *)secret;
+         return (void *) ucp->uc_mcontext.pc;
+@@ -1021,7 +1024,7 @@ void debug::dumpCallstack(MessageHandler *messageHandler, int callstackLevelsToS
+         writeStackTrace(trace, size, callstackLevelsToSkip + 1, lines);     // + 1 to skip the call to dumpCallstack
+ 
+         for (uint i = 0; i < lines.count(); i++) {
+-            messageHandler->log(lines[i], NULL);
++            messageHandler->log(lines[i], va_list());
+             delete lines[i];
+         }
+     }
+-- 
Index: libraries/source/nvtt/patches/pr270.patch
===================================================================
--- /dev/null
+++ libraries/source/nvtt/patches/pr270.patch
@@ -0,0 +1,21 @@
+---
+ src/nvconfig.h.in | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/nvconfig.h.in b/src/nvconfig.h.in
+index 16da646..6a8ad2c 100644
+--- a/src/nvconfig.h.in
++++ b/src/nvconfig.h.in
+@@ -1,7 +1,11 @@
+ #ifndef NV_CONFIG
+ #define NV_CONFIG
+ 
++#if NV_OS_DARWIN && !NV_OS_IOS
++#cmakedefine01 HAVE_UNISTD_H
++#else
+ #cmakedefine HAVE_UNISTD_H
++#endif
+ #cmakedefine HAVE_STDARG_H
+ #cmakedefine HAVE_SIGNAL_H
+ #cmakedefine HAVE_EXECINFO_H
+-- 
Index: libraries/source/nvtt/src/src/nvconfig.h.in
===================================================================
--- libraries/source/nvtt/src/src/nvconfig.h.in
+++ libraries/source/nvtt/src/src/nvconfig.h.in
@@ -1,7 +1,11 @@
 #ifndef NV_CONFIG
 #define NV_CONFIG
 
+#if NV_OS_DARWIN && !NV_OS_IOS
+#cmakedefine01 HAVE_UNISTD_H
+#else
 #cmakedefine HAVE_UNISTD_H
+#endif
 #cmakedefine HAVE_STDARG_H
 #cmakedefine HAVE_SIGNAL_H
 #cmakedefine HAVE_EXECINFO_H
Index: libraries/source/nvtt/src/src/nvcore/Debug.cpp
===================================================================
--- libraries/source/nvtt/src/src/nvcore/Debug.cpp
+++ libraries/source/nvtt/src/src/nvcore/Debug.cpp
@@ -665,6 +665,9 @@
 #  elif NV_CPU_PPC
         ucontext_t * ucp = (ucontext_t *)secret;
         return (void *) ucp->uc_mcontext.regs->nip;
+#    elif NV_CPU_ARM
+        ucontext_t * ucp = (ucontext_t *)secret;
+        return (void *) ucp->uc_mcontext.arm_pc;
 #    elif NV_CPU_AARCH64
         ucontext_t * ucp = (ucontext_t *)secret;
         return (void *) ucp->uc_mcontext.pc;
@@ -1021,7 +1024,7 @@
         writeStackTrace(trace, size, callstackLevelsToSkip + 1, lines);     // + 1 to skip the call to dumpCallstack
 
         for (uint i = 0; i < lines.count(); i++) {
-            messageHandler->log(lines[i], NULL);
+            messageHandler->log(lines[i], va_list());
             delete lines[i];
         }
     }