$ SNAP_CONFINE_DEBUG=yes hello-world
DEBUG: security tag: snap.hello-world.hello-world
DEBUG: executable:   /usr/lib/snapd/snap-exec
DEBUG: confinement:  non-classic
DEBUG: base snap:    core
DEBUG: ruid: 5007, euid: 0, suid: 0
DEBUG: rgid: 502, egid: 0, sgid: 0
DEBUG: apparmor label on snap-confine is: /usr/lib/snapd/snap-confine
DEBUG: apparmor mode is: enforce
DEBUG: checking if the current process shares mount namespace with the init process
DEBUG: re-associating is not required
DEBUG: creating lock directory /run/snapd/lock (if missing)
DEBUG: opening lock directory /run/snapd/lock
DEBUG: opening lock file: /run/snapd/lock/.lock
DEBUG: sanity timeout initialized and set for three seconds
DEBUG: acquiring exclusive lock (scope (global))
DEBUG: sanity timeout reset and disabled
DEBUG: ensuring that snap mount directory is shared
DEBUG: unsharing snap namespace directory
DEBUG: creating namespace group directory /run/snapd/ns
DEBUG: namespace group directory does not require intialization
DEBUG: releasing lock (scope: (global))
DEBUG: snap-update-ns executable: /usr/lib/snapd/snap-update-ns
DEBUG: opened snap-update-ns executable as file descriptor 3
DEBUG: creating lock directory /run/snapd/lock (if missing)
DEBUG: opening lock directory /run/snapd/lock
DEBUG: opening lock file: /run/snapd/lock/hello-world.lock
DEBUG: sanity timeout initialized and set for three seconds
DEBUG: acquiring exclusive lock (scope hello-world)
DEBUG: sanity timeout reset and disabled
DEBUG: initializing mount namespace: hello-world
DEBUG: opening namespace group directory /run/snapd/ns
DEBUG: found base snap filesystem device 7:0
DEBUG: sanity timeout initialized and set for three seconds
DEBUG: receiving information about the state of the mount namespace
DEBUG: ensuring that parent process is still alive
DEBUG: joining the namespace that we are about to probe
DEBUG: found root filesystem inside the mount namespace 7:0
DEBUG: sending information about the state of the mount namespace (keep)
DEBUG: support process for mount namespace inspection is about to finish
DEBUG: sanity timeout reset and disabled
DEBUG: the mount namespace is up-to-date and can be reused
DEBUG: attempting to re-associate the mount namespace with the namespace group hello-world
DEBUG: successfully re-associated the mount namespace with the namespace group hello-world
DEBUG: releasing resources associated with namespace group hello-world
DEBUG: moved process 26002 to freezer cgroup hierarchy for snap hello-world
DEBUG: releasing lock (scope: hello-world)
DEBUG: resetting PATH to values in sync with core snap
DEBUG: snappy_udev_init
DEBUG: creating user data directory: /home/users/nate/snap/hello-world/27
cannot create user data directory: /home/users/nate/snap/hello-world/27: Permission denied


$ dmesg | grep DENIED
[95039.139543] audit: type=1400 audit(1528939068.083:97): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=15994 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[95053.000050] audit: type=1400 audit(1528939081.943:98): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=16200 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[95491.603051] audit: type=1400 audit(1528939520.545:99): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=16741 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[95690.135868] audit: type=1400 audit(1528939719.077:166): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=17631 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[95695.663125] audit: type=1400 audit(1528939724.605:167): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=17738 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[95696.514752] audit: type=1400 audit(1528939725.457:168): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=17837 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96014.661651] audit: type=1400 audit(1528940043.604:235): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=18945 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96019.270841] audit: type=1400 audit(1528940048.212:236): apparmor="DENIED" operation="mkdir" profile="snap.minecraft.minecraft" name="/run/user/0/" pid=19164 comm="mkdir" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
[96054.671790] audit: type=1400 audit(1528940083.612:237): apparmor="DENIED" operation="open" profile="snap.minecraft.minecraft" name="/home/users/daniel/" pid=19054 comm="java" requested_mask="r" denied_mask="r" fsuid=0 ouid=5000
[96055.282515] audit: type=1400 audit(1528940084.224:238): apparmor="DENIED" operation="capable" profile="snap.minecraft.minecraft" pid=19054 comm="java" capability=2  capname="dac_read_search"
[96055.282519] audit: type=1400 audit(1528940084.224:239): apparmor="DENIED" operation="capable" profile="snap.minecraft.minecraft" pid=19054 comm="java" capability=1  capname="dac_override"
[96093.407879] audit: type=1400 audit(1528940122.348:240): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=19352 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96111.958046] audit: type=1400 audit(1528940140.900:241): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=19499 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96140.982435] audit: type=1400 audit(1528940169.923:242): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=19608 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96163.091757] audit: type=1400 audit(1528940192.031:243): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/daniel/" pid=19714 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5000 ouid=5000
[96621.065051] audit: type=1400 audit(1528940650.002:244): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=20766 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[96642.584317] audit: type=1400 audit(1528940671.522:250): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=21007 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97068.247953] audit: type=1400 audit(1528941097.189:251): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=24517 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97108.977797] audit: type=1400 audit(1528941137.917:252): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=24526 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97125.713143] audit: type=1400 audit(1528941154.653:253): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=24533 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97144.870563] audit: type=1400 audit(1528941173.809:254): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=24640 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97591.391324] audit: type=1400 audit(1528941620.328:255): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=25385 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97673.846024] audit: type=1400 audit(1528941702.784:256): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=25411 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97693.902588] audit: type=1400 audit(1528941722.840:257): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=25422 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[97899.984210] audit: type=1400 audit(1528941928.919:258): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=25641 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007
[98321.427664] audit: type=1400 audit(1528942350.366:259): apparmor="DENIED" operation="open" profile="/usr/lib/snapd/snap-confine" name="/home/users/nate/" pid=26002 comm="snap-confine" requested_mask="r" denied_mask="r" fsuid=5007 ouid=5007