Description of problem:
Problem occurred while accesing an image file on Thunar.  The description on SELinux Troubleshooter mentions an apparently nonexistent path beginning with /newroot/, so I cannot check its stated context.
SELinux is preventing bwrap from 'mounton' accesses on the directory /newroot/usr/lib/fontconfig/cache.

*****  Plugin restorecon (99.5 confidence) suggests   ************************

If you want to fix the label. 
/newroot/usr/lib/fontconfig/cache default label should be default_t.
Then you can run restorecon. The access attempt may have been stopped due to insufficient permissions to access a parent directory in which case try to change the following command accordingly.
Do
# /sbin/restorecon -v /newroot/usr/lib/fontconfig/cache

*****  Plugin catchall (1.49 confidence) suggests   **************************

If you believe that bwrap should be allowed mounton access on the cache directory by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# ausearch -c 'bwrap' --raw | audit2allow -M my-bwrap
# semodule -X 300 -i my-bwrap.pp

Additional Information:
Source Context                unconfined_u:unconfined_r:thumb_t:s0-s0:c0.c1023
Target Context                system_u:object_r:fonts_cache_t:s0
Target Objects                /newroot/usr/lib/fontconfig/cache [ dir ]
Source                        bwrap
Source Path                   bwrap
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           
SELinux Policy RPM            selinux-policy-targeted-42.19-1.fc43.noarch
Local Policy RPM              selinux-policy-targeted-42.19-1.fc43.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 6.17.12-300.fc43.x86_64 #1 SMP
                              PREEMPT_DYNAMIC Sat Dec 13 05:06:24 UTC 2025
                              x86_64
Alert Count                   14
First Seen                    2025-12-22 23:50:29 CET
Last Seen                     2025-12-24 16:43:20 CET
Local ID                      7c78aebf-6e6f-4f3a-a99b-e5485db529f7

Raw Audit Messages
type=AVC msg=audit(1766591000.452:612): avc:  denied  { mounton } for  pid=2706730 comm="bwrap" path="/newroot/usr/lib/fontconfig/cache" dev="nvme0n1p3" ino=1713929 scontext=unconfined_u:unconfined_r:thumb_t:s0-s0:c0.c1023 tcontext=system_u:object_r:fonts_cache_t:s0 tclass=dir permissive=0


Hash: bwrap,thumb_t,fonts_cache_t,dir,mounton

Version-Release number of selected component:
selinux-policy-targeted-42.19-1.fc43.noarch

Additional info:
reporter:       libreport-2.17.15
hashmarkername: setroubleshoot
package:        selinux-policy-targeted-42.19-1.fc43.noarch
type:           libreport
reason:         SELinux is preventing bwrap from 'mounton' accesses on the directory /newroot/usr/lib/fontconfig/cache.
component:      selinux-policy
comment:        Problem occurred while accesing an image file on Thunar.  The description on SELinux Troubleshooter mentions an apparently nonexistent path beginning with /newroot/, so I cannot check its stated context.
kernel:         6.17.12-300.fc43.x86_64
component:      selinux-policy