diff --git a/build-envs/README b/build-envs/README
index 234f7a826822a05acc1bf23e885adc30771bf6ba..e48c4ffd8d92db5ad508ee37fa278c4cdf285b75 100644
--- a/build-envs/README
+++ b/build-envs/README
@@ -25,6 +25,13 @@ Running things by hand
 
   $ docker pull registry.gitlab.com/cerl/maestro/maestro-core/buildenv/debian
   $ docker run --ulimit memlock=133000:133000 -i -t registry.gitlab.com/cerl/maestro/maestro-core/buildenv/debian /bin/bash 
+
+  # but since you're reading this, you may be interested in debugging. In that
+  # case, to permit gdb to work inside the docker container you might want to
+  # use
+  #  docker run --cap-add=SYS_PTRACE --ulimit memlock=133000:133000 -i -t registry.gitlab.com/cerl/maestro/maestro-core/buildenv/debian /bin/bash
+  # instead
+
   # now you have a shell in the docker container that is currently used on gitlab for CI
   $ mkdir /builds
   $ cd /builds
diff --git a/maestro/Makefile.am b/maestro/Makefile.am
index 1ba59acf1c400843643d3ccca77f7852b65de40d..e85e2723928c4a64a01f6db4e5aec1f2bef776ff 100644
--- a/maestro/Makefile.am
+++ b/maestro/Makefile.am
@@ -79,6 +79,10 @@ cdo_sel_parse.c cdo_sel_parse.h: cdo_sel_parse.peg
 
 libmaestro_core_la_LIBADD=$(top_builddir)/deps/libcyaml/libcyaml.la $(top_builddir)/deps/mamba/libmmb.la $(top_builddir)/deps/c-timestamp/libtimestamp.la
 
+if NUMA_ENABLED
+libmaestro_core_la_LIBADD+=-lnuma
+endif
+
 # Conductor implementation varies depending on configuration
 if WITH_OFI_POOL_MANAGER
 libmaestro_core_la_SOURCES+=pool_manager_ofi.c ofi.c drc.c
diff --git a/maestro/i_maestro_numa.h b/maestro/i_maestro_numa.h
index 205d92db9942fc0d79c57fa0b12af28574fdb981..001029f09d8b6c78e09cb0053be64f84ee9ca219 100644
--- a/maestro/i_maestro_numa.h
+++ b/maestro/i_maestro_numa.h
@@ -68,8 +68,8 @@ mstro_numa__node_for_addr(void * addr)
 		    addr, MPOL_F_NODE | MPOL_F_ADDR);
     if(s<0) {
       LOG_WARN(MSTRO_LOG_MODULE_CORE,
-	       "Failed to obtain NUMA info for addr %p: %l (%s)\n",
-	       addr, s, strerror(s));
+	       "Failed to obtain NUMA info for addr %p: %ld (%s)\n",
+	       addr, s, strerror(-s));
       return 0;
     } else {
       return node;