no target specified. Pass a positional `<TARGET>` to pack on

Error message

no target specified. Pass a positional `<TARGET>` to pack one function as the binary's only entry point, or one or more `-f <NAME>` flags to pack a subcommand binary.

What it means

validate_flags rejects a `baml pack` invocation that names no pack target at all: neither a positional `<TARGET>` nor any `-f <NAME>` flag was given. Since `baml pack` cannot infer which function(s) to package, it bails with guidance on the two supported targeting styles.

Source

Thrown at baml_language/crates/baml_cli/src/pack_command.rs:252

        if let Some(target) = self.target.as_deref() {
            if looks_like_path(target) {
                anyhow::bail!(
                    "positional `<TARGET>` is a function name, not a file path. \
                     For a single-file source, use `--file {target}` and pass the \
                     function via `-f <NAME>`. For example:\n\
                     \n    `baml pack --file {target} -f <NAME>`\n",
                );
            }
            if !self.functions.is_empty() {
                anyhow::bail!(
                    "positional `<TARGET>` and `-f/--function` are mutually exclusive — \
                     use one or the other (positional packs a single-entry binary; \
                     `-f` produces a subcommand binary)."
                );
            }
        }
        if self.target.is_none() && self.functions.is_empty() {
            anyhow::bail!(
                "no target specified. Pass a positional `<TARGET>` to pack one \
                 function as the binary's only entry point, or one or more \
                 `-f <NAME>` flags to pack a subcommand binary."
            );
        }
        Ok(())
    }

    fn resolved_target_triple(&self) -> Result<&str> {
        match self.target_triple.as_deref() {
            Some(target) => validate_release_target_triple(target),
            None => release_host_target_triple(),
        }
    }

    fn load_and_compile(&self, reporter: &Reporter) -> Result<(ProjectDatabase, Program, bool)> {
        if let Some(file) = self.file.as_deref() {
            // Standalone `--file` mode has no project root, so there is no

View on GitHub (pinned to bd85ce9dee)

Solutions

Pass a positional `<TARGET>` to pack one function as the binary's only entry point, e.g. `baml pack MyFunction`.
Pass one or more `-f <NAME>` flags to pack a subcommand binary, e.g. `baml pack -f Foo -f Bar`.
Use `baml run --list` to see available function names if unsure what to target.

Example fix

// before
baml pack

// after
baml pack MyFunction
// or
baml pack -f MyFunction

Defensive patterns

Strategy: validation

Validate before calling

// ensure at least one target before invoking
if [ -z "$TARGET" ] && [ -z "$FUNCTIONS" ]; then
  echo "usage: baml pack <TARGET> | baml pack -f NAME [-f NAME...]" >&2; exit 2
fi
baml pack $TARGET $FUNCTIONS

Prevention

Never invoke bare `baml pack`; always include a positional target or at least one `-f` flag.
In scripts, fail early if target variables are empty (use ${VAR:?} expansion).
Use `baml run --list` to pick valid targets when composing commands.

When it happens

Trigger: Running bare `baml pack` (or `baml pack --file <PATH>` with no `-f` and no positional) with no target and no functions specified.

Common situations: Users type `baml pack` expecting it to pack the whole project by default; a script drops the positional because a variable is empty; someone ports a `baml run` invocation that used different targeting flags.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/ddca06c21f87331b. Report an issue: GitHub.