diff --git a/contrib/packaging/docker/centos7 b/contrib/packaging/docker/centos7
--- a/contrib/packaging/docker/centos7
+++ b/contrib/packaging/docker/centos7
@@ -15,3 +15,6 @@
 
 # For creating repo meta data
 RUN yum install -y createrepo
+
+# For rust extensions
+RUN yum install -y cargo
diff --git a/contrib/packaging/docker/centos8 b/contrib/packaging/docker/centos8
--- a/contrib/packaging/docker/centos8
+++ b/contrib/packaging/docker/centos8
@@ -13,3 +13,6 @@
 
 # For creating repo meta data
 RUN yum install -y createrepo
+
+# For rust extensions
+RUN yum install -y cargo
diff --git a/contrib/packaging/mercurial.spec b/contrib/packaging/mercurial.spec
--- a/contrib/packaging/mercurial.spec
+++ b/contrib/packaging/mercurial.spec
@@ -110,14 +110,14 @@
 LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py install --root="$RPM_BUILD_ROOT"
 cd -
 
-PATH=$PYPATH:$PATH LD_LIBRARY_PATH=$PYPATH make install PYTHON=%{pythonexe} DESTDIR=$RPM_BUILD_ROOT PREFIX=%{hgpyprefix} MANDIR=%{_mandir}
+PATH=$PYPATH:$PATH LD_LIBRARY_PATH=$PYPATH make install PYTHON=%{pythonexe} DESTDIR=$RPM_BUILD_ROOT PREFIX=%{hgpyprefix} MANDIR=%{_mandir} PURE="--rust"
 mkdir -p $RPM_BUILD_ROOT%{_bindir}
 ( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/hg . )
 ( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/python2.? %{pythonhg} )
 
 %else
 
-make install PYTHON=%{pythonexe} DESTDIR=$RPM_BUILD_ROOT PREFIX=%{_prefix} MANDIR=%{_mandir}
+make install PYTHON=%{pythonexe} DESTDIR=$RPM_BUILD_ROOT PREFIX=%{_prefix} MANDIR=%{_mandir} PURE="--rust"
 
 %endif