get emscripten version from pyodide

ci/docker/conda-python-emscripten.dockerfile

@@ -22,7 +22,6 @@ FROM ${repo}:${arch}-conda-python-${python}
 
 ARG selenium_version="4.15.2"
 ARG pyodide_version="0.26.0"
-ARG emscripten_version="3.1.58"
 ARG chrome_version="latest"
 ARG required_python_min="(3,12)"
 # fail if python version < 3.12
@@ -35,18 +34,20 @@ SHELL ["/bin/bash", "--login", "-c", "-o", "pipefail"]
 
 RUN python -m pip install --no-cache-dir selenium==${selenium_version} &&\
     python -m pip install --no-cache-dir --upgrade --pre pyodide-build==${pyodide_version}
-
-COPY ci/scripts/install_emscripten.sh /arrow/ci/scripts/
-RUN bash /arrow/ci/scripts/install_emscripten.sh ~ "${emscripten_version}"
 
-# make sure zlib is cached in the EMSDK folder
-RUN source ~/emsdk/emsdk_env.sh && embuilder --pic build zlib
-
 # install pyodide dist directory to /pyodide
 WORKDIR /
 RUN pyodide_dist_url="https://github.com/pyodide/pyodide/releases/download/${pyodide_version}/pyodide-${pyodide_version}.tar.bz2" && \
     wget -q "${pyodide_dist_url}" -O- |tar -xj
 
+# install correct version of emscripten for this pyodide
+COPY ci/scripts/install_emscripten.sh /arrow/ci/scripts/
+RUN bash /arrow/ci/scripts/install_emscripten.sh ~ /pyodide
+
+# make sure zlib is cached in the EMSDK folder
+RUN source ~/emsdk/emsdk_env.sh && embuilder --pic build zlib
+
+
 # install chrome for testing browser based runner
 # zip needed for chrome, libpthread stubs installs pthread module to cmake, build-essential makes
 # sure that unix make is available in isolated python environments

ci/scripts/install_emscripten.sh

@@ -17,15 +17,18 @@
 # specific language governing permissions and limitations
 # under the License.
 
-# install emscripten sdk version $2 to directory $2/emsdk
+# install emscripten sdk version to match pyodide in $2 to directory $1/emsdk
 
 set -e
 
 target_path=$1
-emscripten_version=$2
+pyodide_path=$2
+
+emscripten_version=$(${pyodide_path}/python -c "import sys;print(*sys._emscripten_info.emscripten_version,sep='.')")
+
 cd ${target_path}
 ls emsdk || git clone https://github.com/emscripten-core/emsdk.git
 cd emsdk 
 ./emsdk install ${emscripten_version} 
 ./emsdk activate ${emscripten_version}
-echo "Installed emsdk to: $1"
+echo "Installed emsdk to: ${target_path}"

docker-compose.yml

@@ -894,7 +894,6 @@ services:
         arch: ${ARCH}
         clang_tools: ${CLANG_TOOLS}
         llvm: ${LLVM}
-        emscripten_version: "3.1.58" # must use correct emscripten for pyodide version
         pyodide_version: "0.26.0"
         chrome_version: "122"
         selenium_version: "4.15.2"