diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9695b4b4..7bb0b8a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,12 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## Unreleased
+- Change default fiber stack limit to the maximum value of a 32 bit signed integer.
+- Some bug fixes with `jpm`
+- Add `os/arch` to get ISA that janet was compiled for
+- Add color to stacktraces via `(dyn :err-color)`
+
 ## 1.2.0 - 2019-08-08
 - Add `take` and `drop` functions that are easier to use compared to the
   existing slice functions.
diff --git a/appveyor.yml b/appveyor.yml
index ef1f09b9..382d9cf3 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -15,9 +15,10 @@ matrix:
 
 # skip unsupported combinations
 init:
-- call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars32.bat"
+    - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars32.bat"
 
 install:
+    - set JANET_BUILD=%appveyor_repo_commit:~0,7%
     - choco install nsis -y -pre
     # Replace makensis.exe and files with special long string build. This should
     # prevent issues when setting PATH during installation.
@@ -27,6 +28,8 @@ install:
     # We need to reload vcvars after refreshing
     - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars32.bat"
     - build_win test-install
+    - set janet_outname=%appveyor_repo_tag_name%
+    - if "%janet_outname%"=="" set janet_outname=v1.2.0
 build: off
 
 only_commits:
@@ -35,8 +38,20 @@ only_commits:
     - src/
 
 artifacts:
-    - path: janet-v1.2.0-windows-installer.exe
-      name: janet-v1.2.0-windows-installer.exe
+    - name: janet.c
+      path: dist\janet.c
+      type: File
+    - name: janet.h
+      path: dist\janet.h
+      type: File
+    - name: janetconf.h
+      path: dist\janetconf.h
+      type: File
+    - name: "janet-$(janet_outname)-windows"
+      path: dist
+      type: Zip
+    - path: "janet-$(janet_outname)-windows-installer.exe"
+      name: "janet-$(janet_outname)-windows-installer.exe"
       type: File
 
 deploy:
@@ -44,7 +59,7 @@ deploy:
   provider: GitHub
   auth_token:
     secure: lwEXy09qhj2jSH9s1C/KvCkAUqJSma8phFR+0kbsfUc3rVxpNK5uD3z9Md0SjYRx
-  artifact: janet-windows
+  artifact: /janet.*/
   draft: true
   on:
       APPVEYOR_REPO_TAG: true
diff --git a/build_win.bat b/build_win.bat
index 054c8a7c..6bda6464 100644
--- a/build_win.bat
+++ b/build_win.bat
@@ -23,36 +23,41 @@
 @set JANET_LINK=link /nologo
 @set JANET_LINK_STATIC=lib /nologo
 
+@rem Add janet build tag
+if not "%JANET_BUILD%" == "" (
+    @set JANET_COMPILE=%JANET_COMPILE% /DJANET_BUILD="\"%JANET_BUILD%\""
+)
+
 mkdir build
 mkdir build\core
 mkdir build\mainclient
 mkdir build\boot
 
 @rem Build the xxd tool for generating sources
-@cl /nologo /c tools/xxd.c /Fobuild\xxd.obj
+cl /nologo /c tools/xxd.c /Fobuild\xxd.obj
 @if errorlevel 1 goto :BUILDFAIL
-@link /nologo /out:build\xxd.exe build\xxd.obj
+link /nologo /out:build\xxd.exe build\xxd.obj
 @if errorlevel 1 goto :BUILDFAIL
 
 @rem Generate the embedded sources
-@build\xxd.exe src\mainclient\init.janet build\init.gen.c janet_gen_init
+build\xxd.exe src\mainclient\init.janet build\init.gen.c janet_gen_init
 @if errorlevel 1 goto :BUILDFAIL
-@build\xxd.exe src\boot\boot.janet build\boot.gen.c janet_gen_boot
+build\xxd.exe src\boot\boot.janet build\boot.gen.c janet_gen_boot
 @if errorlevel 1 goto :BUILDFAIL
 
 @rem Build the generated sources
-@%JANET_COMPILE% /Fobuild\mainclient\init.gen.obj build\init.gen.c
+%JANET_COMPILE% /Fobuild\mainclient\init.gen.obj build\init.gen.c
 @if errorlevel 1 goto :BUILDFAIL
-@%JANET_COMPILE% /Fobuild\boot\boot.gen.obj build\boot.gen.c
+%JANET_COMPILE% /Fobuild\boot\boot.gen.obj build\boot.gen.c
 @if errorlevel 1 goto :BUILDFAIL
 
 @rem Build the bootstrap interpreter
 for %%f in (src\core\*.c) do (
-    @%JANET_COMPILE% /DJANET_BOOTSTRAP /Fobuild\boot\%%~nf.obj %%f
+    %JANET_COMPILE% /DJANET_BOOTSTRAP /Fobuild\boot\%%~nf.obj %%f
     @if errorlevel 1 goto :BUILDFAIL
 )
 for %%f in (src\boot\*.c) do (
-    @%JANET_COMPILE% /DJANET_BOOTSTRAP /Fobuild\boot\%%~nf.obj %%f
+    %JANET_COMPILE% /DJANET_BOOTSTRAP /Fobuild\boot\%%~nf.obj %%f
     @if errorlevel 1 goto :BUILDFAIL
 )
 %JANET_LINK% /out:build\janet_boot.exe build\boot\*.obj
@@ -60,12 +65,12 @@ for %%f in (src\boot\*.c) do (
 build\janet_boot build\core_image.c
 
 @rem Build the core image
-@%JANET_COMPILE% /Fobuild\core_image.obj build\core_image.c
+%JANET_COMPILE% /Fobuild\core_image.obj build\core_image.c
 @if errorlevel 1 goto :BUILDFAIL
 
 @rem Build the sources
 for %%f in (src\core\*.c) do (
-    @%JANET_COMPILE% /Fobuild\core\%%~nf.obj %%f
+    %JANET_COMPILE% /Fobuild\core\%%~nf.obj %%f
     @if errorlevel 1 goto :BUILDFAIL
 )
 
@@ -74,7 +79,7 @@ rc /nologo /fobuild\janet_win.res janet_win.rc
 
 @rem Build the main client
 for %%f in (src\mainclient\*.c) do (
-    @%JANET_COMPILE% /Fobuild\mainclient\%%~nf.obj %%f
+    %JANET_COMPILE% /Fobuild\mainclient\%%~nf.obj %%f
     @if errorlevel 1 goto :BUILDFAIL
 )
 
diff --git a/janet-installer.nsi b/janet-installer.nsi
index b9f9f0f8..417222a6 100644
--- a/janet-installer.nsi
+++ b/janet-installer.nsi
@@ -25,7 +25,19 @@ VIFileVersion "${PRODUCT_VERSION}"
 
 # Basics
 Name "Janet"
-OutFile "janet-v${VERSION}-windows-installer.exe"
+
+# Do some NSIS-fu to figure out at compile time if we are in appveyor
+!define OUTNAME $%APPVEYOR_REPO_TAG_NAME%
+!define "CHECK_${OUTNAME}"
+!define DOLLAR "$"
+!ifdef CHECK_${DOLLAR}%APPVEYOR_REPO_TAG_NAME%
+    # We are not in the appveyor environment, use version name
+    !define OUTNAME_PART v${VERSION}
+!else
+    # We are in appveyor, use git tag name for installer
+    !define OUTNAME_PART ${OUTNAME}
+!endif
+OutFile "janet-${OUTNAME_PART}-windows-installer.exe"
 
 # Some Configuration
 !define APPNAME "Janet"
diff --git a/meson_options.txt b/meson_options.txt
index afa8f0b9..b63c8ec1 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -14,7 +14,7 @@ option('int_types', type : 'boolean', value : true)
 option('recursion_guard', type : 'integer', min : 10, max : 8000, value : 1024)
 option('max_proto_depth', type : 'integer', min : 10, max : 8000, value : 200)
 option('max_macro_expand', type : 'integer', min : 1, max : 8000, value : 200)
-option('stack_max', type : 'integer', min : 8096, max : 1000000000, value : 16384)
+option('stack_max', type : 'integer', min : 8096, max : 0x7fffffff, value : 0x7fffffff)
 
 option('arch_name', type : 'string', value: '')
 option('os_name', type : 'string', value: '')
diff --git a/src/core/array.c b/src/core/array.c
index 62fa7844..39acff80 100644
--- a/src/core/array.c
+++ b/src/core/array.c
@@ -64,7 +64,9 @@ void janet_array_ensure(JanetArray *array, int32_t capacity, int32_t growth) {
     Janet *newData;
     Janet *old = array->data;
     if (capacity <= array->capacity) return;
-    capacity *= growth;
+    int64_t new_capacity = capacity * growth;
+    if (new_capacity > INT32_MAX) new_capacity = INT32_MAX;
+    capacity = (int32_t) new_capacity;
     newData = realloc(old, capacity * sizeof(Janet));
     if (NULL == newData) {
         JANET_OUT_OF_MEMORY;
diff --git a/src/core/fiber.c b/src/core/fiber.c
index d4fa5e82..cb1eea93 100644
--- a/src/core/fiber.c
+++ b/src/core/fiber.c
@@ -87,19 +87,27 @@ void janet_fiber_setcapacity(JanetFiber *fiber, int32_t n) {
     fiber->capacity = n;
 }
 
+/* Grow fiber if needed */
+static void janet_fiber_grow(JanetFiber *fiber, int32_t needed) {
+    int32_t cap = needed > (INT32_MAX / 2) ? INT32_MAX : 2 * needed;
+    janet_fiber_setcapacity(fiber, cap);
+}
+
 /* Push a value on the next stack frame */
 void janet_fiber_push(JanetFiber *fiber, Janet x) {
+    if (fiber->stacktop == INT32_MAX) janet_panic("stack overflow");
     if (fiber->stacktop >= fiber->capacity) {
-        janet_fiber_setcapacity(fiber, 2 * fiber->stacktop);
+        janet_fiber_grow(fiber, fiber->stacktop);
     }
     fiber->data[fiber->stacktop++] = x;
 }
 
 /* Push 2 values on the next stack frame */
 void janet_fiber_push2(JanetFiber *fiber, Janet x, Janet y) {
+    if (fiber->stacktop >= INT32_MAX - 1) janet_panic("stack overflow");
     int32_t newtop = fiber->stacktop + 2;
     if (newtop > fiber->capacity) {
-        janet_fiber_setcapacity(fiber, 2 * newtop);
+        janet_fiber_grow(fiber, newtop);
     }
     fiber->data[fiber->stacktop] = x;
     fiber->data[fiber->stacktop + 1] = y;
@@ -108,9 +116,10 @@ void janet_fiber_push2(JanetFiber *fiber, Janet x, Janet y) {
 
 /* Push 3 values on the next stack frame */
 void janet_fiber_push3(JanetFiber *fiber, Janet x, Janet y, Janet z) {
+    if (fiber->stacktop >= INT32_MAX - 2) janet_panic("stack overflow");
     int32_t newtop = fiber->stacktop + 3;
     if (newtop > fiber->capacity) {
-        janet_fiber_setcapacity(fiber, 2 * newtop);
+        janet_fiber_grow(fiber, newtop);
     }
     fiber->data[fiber->stacktop] = x;
     fiber->data[fiber->stacktop + 1] = y;
@@ -120,9 +129,10 @@ void janet_fiber_push3(JanetFiber *fiber, Janet x, Janet y, Janet z) {
 
 /* Push an array on the next stack frame */
 void janet_fiber_pushn(JanetFiber *fiber, const Janet *arr, int32_t n) {
+    if (fiber->stacktop > INT32_MAX - n) janet_panic("stack overflow");
     int32_t newtop = fiber->stacktop + n;
     if (newtop > fiber->capacity) {
-        janet_fiber_setcapacity(fiber, 2 * newtop);
+        janet_fiber_grow(fiber, newtop);
     }
     memcpy(fiber->data + fiber->stacktop, arr, n * sizeof(Janet));
     fiber->stacktop = newtop;
diff --git a/src/core/vm.c b/src/core/vm.c
index 21bec2e8..7a2016a8 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -628,6 +628,9 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in, JanetFiberStatus status)
 
     VM_OP(JOP_TAILCALL) {
         Janet callee = stack[D];
+        if (fiber->stacktop > fiber->maxstack) {
+            vm_throw("stack overflow");
+        }
         if (janet_checktype(callee, JANET_KEYWORD)) {
             vm_commit();
             callee = resolve_method(callee, fiber);
diff --git a/src/include/janet.h b/src/include/janet.h
index b8c651db..1d597ae9 100644
--- a/src/include/janet.h
+++ b/src/include/janet.h
@@ -171,11 +171,10 @@ extern "C" {
 /* Maximum depth to follow table prototypes before giving up and returning nil. */
 #define JANET_MAX_MACRO_EXPAND 200
 
-/* Define max stack size for stacks before raising a stack overflow error.
- * If this is not defined, fiber stacks can grow without limit (until memory
- * runs out) */
+/* Define default max stack size for stacks before raising a stack overflow error.
+ * This can also be set on a per fiber basis. */
 #ifndef JANET_STACK_MAX
-#define JANET_STACK_MAX 16384
+#define JANET_STACK_MAX 0x7fffffff
 #endif
 
 /* Use nanboxed values - uses 8 bytes per value instead of 12 or 16.