make linkcheck ignores URLs with anchor tags

[mstpn]

When I was running make linkcheck for changes to a recent PR, I noticed that a number of links were marked as -ignored that I didn't expect.

...
(           index: line   46) -ignored- https://web.libera.chat/#ubuntu-cloud                                                                                                                  
(           index: line   47) -ignored- #public-images-contribute                                                                                                                              
(public-images-explanation/index: line    8) -ignored- #lxd-openstack-images                                                                                                                   
(public-images-explanation/index: line    9) -ignored- #vagrant-explanation                                                                                                                    
(public-images-explanation/lxd-openstack-images: line   53) -ignored- #lxd-tarball-ref                                                                                                         
(public-images-explanation/lxd-openstack-images: line   61) -ignored- #root-tarball-ref                                                                                                        
(public-images-explanation/lxd-openstack-images: line   63) -ignored- #squashfs-ref                                                                                                            
(public-images-explanation/lxd-openstack-images: line   65) -ignored- #qcow-ref                                                                                                                
(public-images-explanation/lxd-openstack-images: line   97) -ignored- https://docs.openstack.org/ocata/admin-guide/common/cli-manage-images.html#create-or-update-an-image-glance              
(public-images-explanation/vagrant: line   25) -ignored- #public-images-how-to                                                                                                                 
(public-images-how-to/build-vagrant-with-bartender: line   88) -ignored- #run-a-vagrant-box                                                                                                    
(public-images-how-to/contribute-to-these-docs: line   51) -ignored- https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-toctree                             
(public-images-how-to/index: line    7) -ignored- #vagrant-bartender                                                                                                                           
(public-images-how-to/index: line    8) -ignored- #use-local-cloud-init-ds                                                                                                                     
(public-images-how-to/index: line    9) -ignored- #launch-libvirt                                                                                                                              
(public-images-how-to/index: line   10) -ignored- #qcow-qemu                                                                                                                                   
(public-images-how-to/index: line   12) -ignored- #run-an-ova-using-virtualbox                                                                                                                 
(public-images-how-to/launch-with-libvirt: line   18) -ignored- #specify-cloud-init-user-data                                                                                                  
(public-images-how-to/run-a-vagrant-box: line   55) -ignored- https://git.launchpad.net/livecd-rootfs/tree/live-build/ubuntu-cpc/hooks.d/base/vagrant.binary#n141                              
(public-images-how-to/run-an-ova-using-virtualbox: line    6) -ignored- https://documentation.ubuntu.com/public-images/en/latest/public-images-reference/artifacts/#ova                        
(public-images-how-to/use-local-cloud-init-ds: line   50) -ignored- https://cloudinit.readthedocs.io/en/latest/explanation/instancedata.html#instance-metadata    
...

It looks like the linkcheck function is erroneously marking any URL containing a hashtag (#) as a link that should be ignored. This is an error, as any URL with an anchor link isn't being tested for validity.

[k-dimple]

Hi Matthew, this was done on purpose to avoid the generation of broken link errors for links like https://ubuntu.com/aws#get-in-touch (which in fact is not broken). We'll see if we can figure out a better way to handle this.