Warn users about 20GiB COPY Docker bug

See #99

Author: slonopotamus

ue4docker/build.py

@@ -237,7 +237,7 @@ def build():
                 )
                 sys.exit(1)
             elif newer_check is None:
-                logger.info(
+                logger.warning(
                     "Warning: unable to determine whether host system is new enough to use specified base tag"
                 )
 

ue4docker/diagnostics/diagnostic_20gig.py

@@ -40,9 +40,8 @@ def getDescription(self):
         return "\n".join(
             [
                 "This diagnostic determines if the Docker daemon suffers from 20GiB COPY bug",
-                "reported at https://github.com/moby/moby/issues/37352 (affects Windows containers only)",
                 "",
-                "#37352 was fixed in https://github.com/moby/moby/pull/41636 but that fix was not released yet",
+                "See https://github.com/adamrehn/ue4-docker/issues/99#issuecomment-1079702817 for details and workarounds",
                 "",
                 self._parser.format_help(),
             ]

ue4docker/infrastructure/BuildConfiguration.py

@@ -530,6 +530,26 @@ def __init__(self, parser, argv, logger):
             "templates": ExcludedComponent.Templates in self.excludedComponents,
         }
 
+        # Warn user that they are in danger of Docker 20GB COPY bug
+        # Unfortunately, we don't have a cheap way to check whether user environment is affected
+        # See https://github.com/adamrehn/ue4-docker/issues/99
+        if self.containerPlatform == "windows":
+            if ExcludedComponent.Debug not in self.excludedComponents:
+                logger.warning("Warning: You didn't pass --exclude debug", False)
+            if not self.custom and semver.VersionInfo.parse(
+                self.release
+            ) >= semver.VersionInfo(5, 0):
+                logger.warning("Warning: You're building Unreal Engine 5", False)
+
+            logger.warning("Warning: You might hit Docker 20GiB COPY bug", False)
+            logger.warning(
+                "Warning: Make sure that `ue4-docker diagnostics 20gig` passes", False
+            )
+            logger.warning(
+                "Warning: See https://github.com/adamrehn/ue4-docker/issues/99#issuecomment-1079702817 for details and workarounds",
+                False,
+            )
+
         # If we're building Windows containers, generate our Windows-specific configuration settings
         if self.containerPlatform == "windows":
             self._generateWindowsConfig()