Incoporate review comments

Author: xhochy

src/maintainer/maintainer_faq.rst

@@ -71,4 +71,6 @@ FAQ
 
 :ref:`(Q) <mfaq_docker_139>` **How to fix "build-locally.py fails with exit code 139"?**
 
-    With Linux Kernel 4.11 there were some changes in the ``vsyscall`` linking. Depending on your distribution this may cause the above error. You can fix that on Debian by editing ``/etc/default/grub`` and specifiy ``GRUB_CMDLINE_LINUX_DEFAULT="vsyscall=emulate"`` in this file. Afterwards, you need run ``update-grub`` and reboot your system. On other Linux distributions the fix is similar but you need to edit a different configuration file to change the Linux kernel cmdline.
+    With Linux Kernel 4.11 there were some changes in the ``vsyscall`` linking. Depending on your distribution this may cause the above error. You can fix that on Debian by editing ``/etc/default/grub`` and specifiy ``GRUB_CMDLINE_LINUX_DEFAULT="vsyscall=emulate"`` in this file. Afterwards, you need run ``update-grub`` and reboot your system. On other Linux distributions the fix is similar but you need to edit a different configuration file to change the Linux kernel cmdline. This workaround is only needed for images based on CentOS 6 (``cos6``). You could also workaround this by forcing the CentOS 7 based images using ``DOCKER_IMAGE=quay.io/condaforge/linux-anvil-cos7-x86_64 ./build-locally.py``.
+
+    The exit code 139 itself actually is the general exit code for a segmentation fault. This could also mean that you have run into a different issue but the above issue is the most likely one with our CentOS 6-based images.