fixing few errors in build with headers and musl

scripts/headers.sh

@@ -15,7 +15,7 @@ if command -v "clang" >/dev/null 2>&1 && command -v "lld" >/dev/null 2>&1; then
         export LLVM_IAS=1
 fi
 
-if [ -z ./build/"$LINUX_SOURCE" ]; then
+if [ ! -d ./build/"$LINUX_SOURCE" ]; then
         echo "Extracting Linux tarball to ./build/"
         tar -xpf ./sources/"$LINUX_TAR" -C ./build
 else
@@ -37,7 +37,6 @@ make mrproper
 make headers
 find usr/include -type f ! -name '*.h' -delete
 cp -rv usr/include/* ../"$FROOT"/include/
-rm -v ../"$FROOT"/include/Makefile
 
 exit
 

scripts/musl.sh

@@ -2,7 +2,7 @@
 set -eu
 
 ARCH=$(uname -m)
-FROOT="$ARCH-musllvm"
+FROOT="./build/$ARCH-musllvm"
 MUSL_TAR=$(ls ./sources/musl-*.tar.* 2>/dev/null | head -n 1 | xargs basename)
 if [ -z "$MUSL_TAR" ]; then
         echo "ERR: No Musl tarball found in sources directory"