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Command Reference

ue4-docker diagnostics

Contents

Runs diagnostics to detect issues with the host system configuration.

Usage syntax:

ue4-docker diagnostics DIAGNOSTIC

This command can be used to run the following diagnostics:

Checking for the Docker 8GiB filesystem layer bug

Some versions of Docker contain one or more of a series of separate but related bugs that prevent the creation of filesystem layers which are 8GiB in size or larger. This also causes COPY directives to fail when copying data in excess of 8GiB in size, breaking Dockerfile steps during the creation of Installed Builds that contain debug symbols.

This diagnostic tests whether the host system’s Docker daemon suffers from this issue, by attempting to build a simple test Dockerfile with an 8GiB filesystem layer:

ue4-docker diagnostics 8gig

Checking for the Windows Host Compute Service (HCS) storage-opt bug

Windows Server versions 1903 and 1909 and Windows 10 versions 1903 and 1909 contain a bug in the Host Compute Service (HCS) that prevents users from increasing the maximum allowed image size using Docker’s storage-opt configuration key. Since Unreal Engine containers require a far higher limit than the default during builds, this bug prevents the ue4-docker build command from functioning correctly on affected systems.

This diagnostic tests whether the host system is affected this bug, by attempting to run a container with a non-default storage-opt value:

ue4-docker diagnostics maxsize

Checking for container network connectivity issues

This diagnostic tests whether running containers are able to access the internet, resolve DNS entries, and download remote files:

ue4-docker diagnostics network