diff --git a/.cargo/config b/.cargo/config
new file mode 100644
index 000000000..93b20ab3f
--- /dev/null
+++ b/.cargo/config
@@ -0,0 +1,2 @@
+[unstable]
+namespaced-features = true
\ No newline at end of file
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
new file mode 100644
index 000000000..a0eefd3a9
--- /dev/null
+++ b/.github/workflows/rust.yml
@@ -0,0 +1,24 @@
+name: Rust
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly
+          target: thumbv7em-none-eabi
+          override: true
+      - name: Build
+        run: ./test-build.sh
diff --git a/embassy-net/Cargo.toml b/embassy-net/Cargo.toml
index aec6b7965..185992ddc 100644
--- a/embassy-net/Cargo.toml
+++ b/embassy-net/Cargo.toml
@@ -11,6 +11,7 @@ defmt-debug = []
 defmt-info = []
 defmt-warn = []
 defmt-error = []
+defmt = [ "dep:defmt", "smoltcp/defmt" ]
 
 [dependencies]
 
diff --git a/embassy-net/src/tcp_socket.rs b/embassy-net/src/tcp_socket.rs
index 7f4eb014c..eab8189de 100644
--- a/embassy-net/src/tcp_socket.rs
+++ b/embassy-net/src/tcp_socket.rs
@@ -112,7 +112,6 @@ impl<'a> TcpSocket<'a> {
 }
 
 fn to_ioerr(e: Error) -> io::Error {
-    warn!("smoltcp err: {:?}", e);
     // todo
     io::Error::Other
 }
diff --git a/test-build.sh b/test-build.sh
index f67cc5b2b..ec35f5da3 100755
--- a/test-build.sh
+++ b/test-build.sh
@@ -2,24 +2,12 @@
 
 set -euxo pipefail
 
-# embassy std
-(cd embassy; cargo build --features log,std)
+# build for std
+(cd embassy-net; cargo build --features log)
 
-# embassy embedded
-(cd embassy; cargo build --target thumbv7em-none-eabi)
-(cd embassy; cargo build --target thumbv7em-none-eabi --features log)
-(cd embassy; cargo build --target thumbv7em-none-eabi --features defmt)
-
-# embassy-nrf
-
-(cd embassy-nrf-examples; cargo build --target thumbv7em-none-eabi --bins)
-
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52810)
-#(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52811)  # nrf52811-hal doesn't exist yet
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52832)
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52833)
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52840)
-
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52840,log)
-(cd embassy-nrf; cargo build --target thumbv7em-none-eabi --features 52840,defmt)
+# build for embedded
+(cd embassy-net; cargo build --target thumbv7em-none-eabi --features log)
+(cd embassy-net; cargo build --target thumbv7em-none-eabi --features defmt)
 
+# build examples
+(cd embassy-net-examples; cargo build)