update build.yml

Author: daleroberts

.github/workflows/build.yml

@@ -223,7 +223,7 @@ jobs:
             /usr/local/lib/libxerces-c*.a
             /usr/local/include/xercesc
             /usr/local/lib/pkgconfig/xerces-c.pc
-          key: xerces-static-${{ env.XERCES_VERSION }}-${{ runner.os }}
+          key: xerces-static-${{ env.XERCES_VERSION }}-${{ runner.os }}-fPIC
 
       - name: Build static xerces
         if: steps.cache-xerces.outputs.cache-hit != 'true'
@@ -235,7 +235,7 @@ jobs:
 
           cd xerces-c-${{ env.XERCES_VERSION }}
 
-          PKG_CONFIG="pkg-config --static" ./configure --without-curl --without-icu --enable-static --disable-shared
+          PKG_CONFIG="pkg-config --static" CFLAGS="-fPIC" CXXFLAGS="-fPIC" ./configure --without-curl --without-icu --enable-static --disable-shared
           make -j2
           sudo make install