ssh -Xしてfirefoxを起動しようとしても下のようなエラーが出るとき
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/local/share/doc /usr/local/share/doc none bind,ro 0 0): cannot open directory "/usr/local/share": permission denied
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/gimp/2.0/help /usr/share/gimp/2.0/help none bind,ro 0 0): cannot write to "/var/lib/snapd/hostfs/usr/share/gimp/2.0/help" because it would affect the host in "/var/lib/snapd"
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/libreoffice/help /usr/share/libreoffice/help none bind,ro 0 0): cannot write to "/var/lib/snapd/hostfs/usr/share/libreoffice/help" because it would affect the host in "/var/lib/snapd"
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/sphinx_rtd_theme /usr/share/sphinx_rtd_theme none bind,ro 0 0): cannot write to "/var/lib/snapd/hostfs/usr/share/sphinx_rtd_theme" because it would affect the host in "/var/lib/snapd"
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/xubuntu-docs /usr/share/xubuntu-docs none bind,ro 0 0): cannot write to "/var/lib/snapd/hostfs/usr/share/xubuntu-docs" because it would affect the host in "/var/lib/snapd"
次の環境変数をサーバー側に設定します。
export XAUTHORITY=$HOME/.Xauthority
参考