permission denied ": unknown"

Hi,

I'm using Fedora 30

**$ docker --version**
Docker version 19.03.2, build 6a30dfc
**$ docker-slim -v**
docker-slim version linux|Transformer|1.25.3|b5aef546a575de242b2c3ace97e1fc11f028b137|2019-08-04_04:31:18PM
**$ which docker-slim** 
/usr/local/bin/docker-slim

on a totally clean install of docker, I'm seeing the following error.

**docker pull ubuntu:14.04**

14.04: Pulling from library/ubuntu
a7344f52cb74: Pull complete 
515c9bb51536: Pull complete 
e1eabe0537eb: Pull complete 
4701f1215c13: Pull complete 
Digest: sha256:2f7c79927b346e436cc14c92bd4e5bd778c3bd7037f35bc639ac1589a7acfa90
Status: Downloaded newer image for ubuntu:14.04
docker.io/library/ubuntu:14.04



 **$ sudo docker-slim build ubuntu:14.04**

docker-slim[build]: info=http.probe message='using default probe'
docker-slim[build]: state=started
docker-slim[build]: info=params target=ubuntu:14.04 continue.mode=enter
docker-slim[build]: state=image.inspection.start
docker-slim[build]: info=image id=sha256:2c5e00d77a67934d5e39493477f262b878f127b9c01b491f06d8f06f78819578 size.bytes=188195735 size.human=188 MB
docker-slim[build]: info=image.stack index=0 name='ubuntu:14.04' id='sha256:2c5e00d77a67934d5e39493477f262b878f127b9c01b491f06d8f06f78819578'
docker-slim[build]: state=image.inspection.done
docker-slim[build]: state=container.inspection.start
docker-slim[build]: info=container status=created id=f71c98947c6b7e309625dfb295c2a1996cedf7ee798c3fa99ad5ecfe1bfeb923
time="2019-10-01T11:33:46+01:00" level=fatal msg="docker-slim: failure" error="API error (400): {"message":"OCI runtime create failed: container_linux.go:345: starting container process caused \"exec: \\\"/opt/dockerslim/bin/sensor\\\": permission denied\": unknown"}
" stack="goroutine 1 [running]:
runtime/debug.Stack(0x1, 0xc0001e6480, 0xc00002f400)
	/usr/local/Cellar/go/1.11.1/libexec/src/runtime/debug/stack.go:24 +0xa7
github.com/docker-slim/docker-slim/pkg/util/errutil.FailOn(0x98ad80, 0xc0004a8080)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/pkg/util/errutil/errutil.go:14 +0x51
github.com/docker-slim/docker-slim/internal/app/master/commands.OnBuild(0x86d701, 0x0, 0x0, 0x0, 0xc00022e280, 0xe, 0xc0001760c0, 0x0, 0x0, 0x7ffc41ee0743, ...)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/commands/build.go:216 +0xfc0
github.com/docker-slim/docker-slim/internal/app/master.init.0.func6(0xc000182140, 0x0, 0xc000182140)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/cli.go:682 +0x1310
github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.HandleAction(0x85c9c0, 0x920a38, 0xc000182140, 0xc00017a000, 0x0)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/app.go:485 +0xc8
github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.Command.Run(0x900af0, 0x5, 0x0, 0x0, 0xc000067870, 0x1, 0x1, 0x919408, 0x3e, 0x0, ...)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/command.go:207 +0x991
github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.(*App).Run(0xc0000aab60, 0xc00001c090, 0x3, 0x3, 0x0, 0x0)
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/app.go:250 +0x6ea
github.com/docker-slim/docker-slim/internal/app/master.runCli()
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/cli.go:1027 +0x55
github.com/docker-slim/docker-slim/internal/app/master.Run()
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/app.go:6 +0x25
main.main()
	/Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/cmd/docker-slim/main.go:8 +0x20
" version="linux|Transformer|1.25.3|b5aef546a575de242b2c3ace97e1fc11f028b137|2019-08-04_04:31:18PM" 

I have also tried running docker-slim as my user, from a local binary, with the correct permissions and I'm getting the same error.

I have asked collegues to test this, and they're seeing the same thing on other OS as well, Pop OS specifically.

Is there any more information I can provide to try and find the source of this problem ?

Reproduce docker-slim build ubuntu:14.04 on the reported Docker and Linux environments, then inspect internal/app/master/commands/build.go around the failing entry point and the /opt/dockerslim/bin/sensor setup. Done means identifying and addressing the cause of the sensor's permission-denied startup failure, with a regression check on the affected environments.