Source:
<code>private org.eclipse.che.api.workspace.server.model.impl.CommandImpl toWorkspaceCommand( Command devCommand, Action commandAction, FileContentProvider contentProvider) throws DevfileException { org.eclipse.che.api.workspace.server.model.impl.CommandImpl command = new org.eclipse.che.api.workspace.server.model.impl.CommandImpl(); command.setName(devCommand.getName()); command.setType(commandAction.getType()); command.setCommandLine(commandAction.getCommand()); if (commandAction.getWorkdir() != null) { command.getAttributes().put(WORKING_DIRECTORY_ATTRIBUTE, commandAction.getWorkdir()); } if (commandAction.getComponent() != null) { command .getAttributes() .put(Constants.COMPONENT_ALIAS_COMMAND_ATTRIBUTE, commandAction.getComponent()); } if (commandAction.getReference() != null) { command.getAttributes().put(COMMAND_ACTION_REFERENCE_ATTRIBUTE, commandAction.getReference()); } if (commandAction.getReferenceContent() != null) { command .getAttributes() .put(COMMAND_ACTION_REFERENCE_CONTENT_ATTRIBUTE, commandAction.getReferenceContent()); } else if (commandAction.getReference() != null) { try { String referenceContent = contentProvider.fetchContent(commandAction.getReference()); command.getAttributes().put(COMMAND_ACTION_REFERENCE_CONTENT_ATTRIBUTE, referenceContent); } catch (IOException e) { throw new DevfileException( format( <START> "Failed to fetch content of action from reference %s", <END> commandAction.getReference()), e); } } command.getAttributes().putAll(devCommand.getAttributes()); return command; }</code><technical_language>I add a error message, otherwise, end-user able original error, 404 Page found, invalid URL. WDYT</technical_language>

Target:
private org.eclipse.che.api.workspace.server.model.impl.CommandImpl toWorkspaceCommand( Command devCommand, Action commandAction, FileContentProvider contentProvider) throws DevfileException { org.eclipse.che.api.workspace.server.model.impl.CommandImpl command = new org.eclipse.che.api.workspace.server.model.impl.CommandImpl(); command.setName(devCommand.getName()); command.setType(commandAction.getType()); command.setCommandLine(commandAction.getCommand()); if (commandAction.getWorkdir() != null) { command.getAttributes().put(WORKING_DIRECTORY_ATTRIBUTE, commandAction.getWorkdir()); } if (commandAction.getComponent() != null) { command .getAttributes() .put(Constants.COMPONENT_ALIAS_COMMAND_ATTRIBUTE, commandAction.getComponent()); } if (commandAction.getReference() != null) { command.getAttributes().put(COMMAND_ACTION_REFERENCE_ATTRIBUTE, commandAction.getReference()); } if (commandAction.getReferenceContent() != null) { command .getAttributes() .put(COMMAND_ACTION_REFERENCE_CONTENT_ATTRIBUTE, commandAction.getReferenceContent()); } else if (commandAction.getReference() != null) { try { String referenceContent = contentProvider.fetchContent(commandAction.getReference()); command.getAttributes().put(COMMAND_ACTION_REFERENCE_CONTENT_ATTRIBUTE, referenceContent); } catch (IOException e) { throw new DevfileException( format( "Failed to fetch content of action from reference %s: %s", commandAction.getReference(), e.getMessage()), e); } } command.getAttributes().putAll(devCommand.getAttributes()); return command; }