diff --git a/py/build_mypyc.sh b/py/build_mypyc.sh
index d5dce31..f99bec6 100755
--- a/py/build_mypyc.sh
+++ b/py/build_mypyc.sh
@@ -4,7 +4,7 @@ cd $(dirname $0)
 source py_env.sh
 rm -rf rbmp
 cp -r src rbmp
-sed -i '' 's/from src./from rbmp./' rbmp/*.py
+sed -i'' 's/from src./from rbmp./' rbmp/*.py
 mypyc rbmp
 
 cat >rosettaboy-mypyc <<EOD
diff --git a/rs/build_lto.sh b/rs/build_lto.sh
index 4cdd990..ab73493 100755
--- a/rs/build_lto.sh
+++ b/rs/build_lto.sh
@@ -3,4 +3,5 @@ set -eu
 
 cd $(dirname $0)
 cargo build --profile release-lto
+rm -f ./rosettaboy-lto
 mv ./target/release-lto/rosettaboy-rs ./rosettaboy-lto
\ No newline at end of file
diff --git a/utils/Dockerfile b/utils/Dockerfile
index 94cbf22..d7ed6e0 100644
--- a/utils/Dockerfile
+++ b/utils/Dockerfile
@@ -17,13 +17,6 @@ USER root
 RUN apt update && apt install -y \
     build-essential linux-perf valgrind vim git libsdl2-dev wget
 
-# To build python (could most of these live in the py-builder image?)
-RUN apt-get install -y --no-install-recommends \
-    make build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev \
-    libsqlite3-dev wget curl llvm libncurses5-dev xz-utils tk-dev \
-    libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
-RUN apt-get install -y mecab-ipadic-utf8
-
 # Configure developer environment
 ARG USER_ID
 ARG GROUP_ID
@@ -77,6 +70,12 @@ RUN git clone https://github.com/Ponup/php-sdl ~/php-sdl && \
 
 FROM base-builder AS py-builder
 ARG PYTHON_VERSION
+USER root
+RUN apt-get install -y --no-install-recommends \
+    make build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev \
+    libsqlite3-dev wget curl llvm libncurses5-dev xz-utils tk-dev \
+    libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev
+RUN apt-get install -y mecab-ipadic-utf8
 USER dev
 RUN git clone --depth=1 https://github.com/yyuu/pyenv /home/dev/.pyenv
 ENV PYENV_ROOT="/home/dev/.pyenv"
@@ -117,7 +116,7 @@ USER root
 RUN apt update && apt install -y cmake clang clang-format-14 libfmt-dev
 
 # Install Go tools
-COPY --from=go-builder /home/dev/.go /home/dev/.go
+COPY --from=go-builder --chown=dev:dev /home/dev/.go /home/dev/.go
 ENV PATH="/home/dev/.go/bin:$PATH"
 
 # Install Nim tools
@@ -126,21 +125,21 @@ COPY --from=nim-builder --chown=dev:dev /home/dev/.nimble /home/dev/.nimble
 ENV PATH="/home/dev/.nimble/bin:$PATH"
 
 # Install PHP tools
-COPY --from=php-builder /home/dev/.php /home/dev/.php
+COPY --from=php-builder --chown=dev:dev /home/dev/.php /home/dev/.php
 ENV PATH="/home/dev/.php/bin:$PATH"
 
 # Install Python tools
-COPY --from=py-builder /home/dev/.pyenv /home/dev/.pyenv
+COPY --from=py-builder --chown=dev:dev /home/dev/.pyenv /home/dev/.pyenv
 ENV PYENV_ROOT="/home/dev/.pyenv"
 ENV PATH="/home/dev/.pyenv/shims:/home/dev/.pyenv/bin:$PATH"
 
 # Install Rust tools
-COPY --from=rs-builder /home/dev/.rustup /home/dev/.rustup
-COPY --from=rs-builder /home/dev/.cargo /home/dev/.cargo
+COPY --from=rs-builder --chown=dev:dev /home/dev/.rustup /home/dev/.rustup
+COPY --from=rs-builder --chown=dev:dev /home/dev/.cargo /home/dev/.cargo
 ENV PATH="/home/dev/.cargo/bin:$PATH"
 
 # Install Zig tools
-COPY --from=zig-builder /home/dev/.zig /home/dev/.zig
+COPY --from=zig-builder --chown=dev:dev /home/dev/.zig /home/dev/.zig
 ENV PATH="/home/dev/.zig:$PATH"
 
 # Get ready to go