diff --git a/emsdk-cc b/emsdk-cc
index 7685aba..e224872 100644
--- a/emsdk-cc
+++ b/emsdk-cc
@@ -125,6 +125,8 @@ WASM_EXTRA = env("WASM_EXTRA", "") + " " + env("WASM_OPTS", "")
 # the only sane default for now
 COPTS = env("COPTS", "-O2 -g3")
 
+SIZEOPT = '-Os' in COPTS
+
 MAIN_MODULE = LINKING = STATIC = False
 
 EXE = False
@@ -366,7 +368,8 @@ else:
                     except Exception as e:
                         dbg("ERROR: 312", e)
 
-        final.append("-sENVIRONMENT=node")
+        if SIZEOPT:
+            final.append("-sENVIRONMENT=node")
 
         # error: explicitly setting EXIT_RUNTIME not compatible with STANDALONE_WASM.
         #  EXIT_RUNTIME will always be True for programs (with a main function) and False for reactors (not main function).
@@ -378,7 +381,7 @@ else:
 
         __import__("atexit").register(make_exe)
     elif HTML:
-        if "-sENVIRONMENT=web" not in out:
+        if SIZEOPT and ("-sENVIRONMENT=web" not in out):
             final.append("-sENVIRONMENT=web")
 
     # maybe not pass all WASM opts when -c + -o but always PIC and opt level
diff --git a/python-wasi-sdk.sh b/python-wasi-sdk.sh
index 491ab66..3235b83 100755
--- a/python-wasi-sdk.sh
+++ b/python-wasi-sdk.sh
@@ -172,10 +172,10 @@ END
             echo "keeping installed wasmtime and wasi binaries"
         else
             #wget https://github.com/bytecodealliance/wasmtime/releases/download/v22.0.0/wasmtime-v22.0.0-x86_64-linux.tar.xz
-
+            # wget https://github.com/bytecodealliance/wasmtime/releases/download/v26.0.1/wasmtime-v26.0.1-$(arch)-$(PLATFORM).tar.xz \
 # TODO: window only has a zip archive, better use wasmtime-py instead.
 
-            wget https://github.com/bytecodealliance/wasmtime/releases/download/v26.0.1/wasmtime-v26.0.1-$(arch)-$(PLATFORM).tar.xz \
+            wget https://github.com/bytecodealliance/wasmtime/releases/download/v27.0.0/wasmtime-v27.0.0-$(arch)-$(PLATFORM).tar.xz \
              -O-|xzcat|tar xfv -
             mv -vf $(find wasmtime*|grep /wasmtime$) ${SDKROOT}/devices/$(arch)/usr/bin
         fi
diff --git a/python-wasm-sdk.sh b/python-wasm-sdk.sh
index 491ab66..3235b83 100755
--- a/python-wasm-sdk.sh
+++ b/python-wasm-sdk.sh
@@ -172,10 +172,10 @@ END
             echo "keeping installed wasmtime and wasi binaries"
         else
             #wget https://github.com/bytecodealliance/wasmtime/releases/download/v22.0.0/wasmtime-v22.0.0-x86_64-linux.tar.xz
-
+            # wget https://github.com/bytecodealliance/wasmtime/releases/download/v26.0.1/wasmtime-v26.0.1-$(arch)-$(PLATFORM).tar.xz \
 # TODO: window only has a zip archive, better use wasmtime-py instead.
 
-            wget https://github.com/bytecodealliance/wasmtime/releases/download/v26.0.1/wasmtime-v26.0.1-$(arch)-$(PLATFORM).tar.xz \
+            wget https://github.com/bytecodealliance/wasmtime/releases/download/v27.0.0/wasmtime-v27.0.0-$(arch)-$(PLATFORM).tar.xz \
              -O-|xzcat|tar xfv -
             mv -vf $(find wasmtime*|grep /wasmtime$) ${SDKROOT}/devices/$(arch)/usr/bin
         fi
diff --git a/wasisdk/hotfix/grp.h b/wasisdk/hotfix/grp.h
index e69de29..8337712 100644
--- a/wasisdk/hotfix/grp.h
+++ b/wasisdk/hotfix/grp.h
@@ -0,0 +1 @@
+//