Thanks!  Please note there is stuff here I have already added to try and figure it out.  But this config did produce the error.  It's inconsistently reproducible.  I was even able to get a tty and run /startup with file not found!  

[bkelly@zbox syncthing]$ cat Dockerfile
FROM fedora:30

MAINTAINER Boyd Kelly <bkelly@coastsystems.net>
RUN dnf -y install syncthing procps-ng iproute

ENV PUID=1000
ENV PGID=1000

RUN groupadd -g "${PGID}" syncthing && useradd -u "${PUID}" -g syncthing -G wheel -d /home/syncthing -s /sbin/nologin -c "Syncthing User" syncthing

RUN useradd -ms /bin/bash bkelly && usermod -aG wheel bkelly
RUN sed -i '/^#auth/s/^#//g' /etc/pam.d/su
RUN sed -e 's;^# \(%wheel.*NOPASSWD.*\);\1;g' -i /etc/sudoers

EXPOSE 8384
COPY startup.sh /

USER syncthing
CMD ["/startup.sh"]
#CMD ["/usr/bin/syncthing -no-browser -no-restart -home /var/syncthing -gui-address 0.0.0.0:8384"]


[bkelly@zbox syncthing]$ podman info --debug
debug:
  compiler: gc
  git commit: ""
  go version: go1.12.5
  podman version: 1.4.2
host:
  BuildahVersion: 1.9.0
  Conmon:
    package: podman-1.4.2-1.fc30.x86_64
    path: /usr/libexec/podman/conmon
    version: 'conmon version 0.2.0, commit: d7234dc01ae2ef08c42e3591e876723ad1c914c9'
  Distribution:
    distribution: fedora
    version: "30"
  MemFree: 76812288
  MemTotal: 2084212736
  OCIRuntime:
    package: runc-1.0.0-93.dev.gitb9b6cc6.fc30.x86_64
    path: /usr/bin/runc
    version: |-
      runc version 1.0.0-rc8+dev
      commit: e3b4c1108f7d1bf0d09ab612ea09927d9b59b4e3
      spec: 1.0.1-dev
  SwapFree: 2136981504
  SwapTotal: 2218782720
  arch: amd64
  cpus: 4
  hostname: zbox
  kernel: 5.1.15-300.fc30.x86_64
  os: linux
  rootless: true
  uptime: 5h 58m 45.26s (Approximately 0.21 days)
registries:
  blocked: null
  insecure: null
  search:
  - docker.io
  - registry.fedoraproject.org
  - quay.io
  - registry.access.redhat.com
  - registry.centos.org
store:
  ConfigFile: /home/bkelly/.config/containers/storage.conf
  ContainerStore:
    number: 10
  GraphDriverName: overlay
  GraphOptions:
  - overlay.mount_program=/usr/bin/fuse-overlayfs
  GraphRoot: /home/bkelly/.local/share/containers/storage
  GraphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  ImageStore:
    number: 95
  RunRoot: /run/user/1000
  VolumePath: /home/bkelly/.local/share/containers/storage/volumes

[bkelly@zbox syncthing]$ cat runit.sh
#!/usr/bin/bash
podman run -d \
  --userns=keep-id \
  --security-opt label=disable \
  --name syncthing \
  -p 8384:8384 \
  -v /var/data/syncthing:/var/syncthing \
  syncthing  


On Thu, Jul 4, 2019 at 9:01 AM Boyd Kelly <bkelly@coastsystems.net> wrote:
Hi,

I'm just exploring podman and buildah, but noticed something weird; not sure if it could be a bug or misconfiguration.  But I don't know where to look for clues as to what is happening.  Sometimes when I start a container I get a file not found error message and then 2 seconds later it starts and runs just fine.  What could be the problem?  Thanks for any suggestions.

(This is a container running Fedora 30)

[bkelly@zbox ~]$ podman container start syncthing
Error: unable to start container "syncthing": time="2019-07-04T07:23:41Z" level=error msg="container_linux.go:346: starting container process caused \"exec: \\\"/startup.sh\\\": stat /startup.sh: no such file or directory\"\n"
container_linux.go:346: starting container process caused "exec: \"/startup.sh\": stat /startup.sh: no such file or directory"
: OCI runtime error
[bkelly@zbox ~]$ podman container start syncthing
syncthing


--
Boyd Kelly
www: http://www.coastsystems.net
Tel: +1 604 837-0765