sipeed/picoclaw · error

failed to set %s: %w

Error message

failed to set %s: %w

What it means

When --host resolves, gateway RunE exports it as the config.EnvGatewayHost environment variable (os.Setenv) so downstream gateway code sees the override, and restores/unsets it via defer. This error wraps an os.Setenv failure. In Go that only happens for an invalid variable name or an OS-level refusal; EnvGatewayHost is a compile-time constant, so in shipped builds this is nearly unreachable.

Source

Thrown at cmd/picoclaw/internal/gateway/command.go:59

				return fmt.Errorf("the --no-truncate option can only be used in conjunction with --debug (-d)")
			}

			if noTruncate {
				utils.SetDisableTruncation(true)
				logger.Info("String truncation is globally disabled via 'no-truncate' flag")
			}

			return nil
		},
		RunE: func(cmd *cobra.Command, _ []string) error {
			resolvedHost, err := resolveGatewayHostOverride(cmd.Flags().Changed("host"), host)
			if err != nil {
				return err
			}
			if resolvedHost != "" {
				prevHost, hadPrev := os.LookupEnv(config.EnvGatewayHost)
				if err := os.Setenv(config.EnvGatewayHost, resolvedHost); err != nil {
					return fmt.Errorf("failed to set %s: %w", config.EnvGatewayHost, err)
				}
				defer func() {
					if hadPrev {
						_ = os.Setenv(config.EnvGatewayHost, prevHost)
						return
					}
					_ = os.Unsetenv(config.EnvGatewayHost)
				}()
			}

			return gateway.Run(debug, internal.GetPicoclawHome(), internal.GetConfigPath(), allowEmpty)
		},
	}

	cmd.Flags().BoolVarP(&debug, "debug", "d", false, "Enable debug logging")
	cmd.Flags().BoolVarP(&noTruncate, "no-truncate", "T", false, "Disable string truncation in debug logs")
	cmd.Flags().BoolVarP(
		&allowEmpty,

View on GitHub (pinned to 49183d7e8d)

Solutions

1. Run without --host and set the gateway host in the config file instead
2. Verify the picoclaw binary integrity and version; report it upstream if reproducible
3. Check for OS environment-size limits if running under unusual wrappers

# practically unneeded; if paranoid, verify env override works first
PICOCLOW_GATEWAY_HOST=127.0.0.1 picoclaw gateway --help >/dev/null && echo env ok

if err := os.Setenv(config.EnvGatewayHost, host); err != nil {
    // do not abort the gateway: fall back to config-file host and log loudly
    logger.WarnF("host override via env failed", map[string]any{"error": err})
}

When it happens

Trigger: os.Setenv(EnvGatewayHost, resolvedHost) returning an error: effectively only a corrupted binary, an invalid constant, or an exotic platform limit (e.g. environment-size E2BIG conditions).

Common situations: Practically never seen; would indicate a build/source corruption or an unusual OS restriction rather than a user mistake.

Related errors

• invalid --host value: %w
• the --no-truncate option can only be used in conjunction wit
• --env can only be used with stdio transport
• --env-file can only be used with stdio transport
• failed to load config: %w

AI-assisted analysis of sipeed/picoclaw@49183d7e8d (2026-08-15). Data as JSON: /api/errors/e300eb8dbe4a3152. Report an issue: GitHub.