Use the musl version from downloads in the metadata

Author: zanieb

cpython-unix/build-cpython.sh

@@ -916,7 +916,6 @@ EOF
 ${BUILD_PYTHON} ${ROOT}/generate_metadata.py ${ROOT}/metadata.json
 cat ${ROOT}/metadata.json
 
-# TODO: Output a dynamic library version for musl
 if [ "${CC}" != "musl-clang" ]; then
     objdump -T ${LIBPYTHON_SHARED_LIBRARY} | grep GLIBC_ | awk '{print $5}' | awk -F_ '{print $2}' | sort -V | tail -n 1 > ${ROOT}/glibc_version.txt
     cat ${ROOT}/glibc_version.txt

cpython-unix/build.py

@@ -845,7 +845,12 @@ def build_cpython(
 
                 if "musl" in target_triple:
                     crt_features.append("musl-dynamic")
-                    # TODO: Determine the dynamic musl libc version
+
+                    musl_version = DOWNLOADS["musl"]["version"]
+                    crt_features.append(
+                        "musl-version:%s"
+                        % musl_version
+                    )
 
                 else:
                     crt_features.append("glibc-dynamic")