What causes "{:?} is not a file" in tauri-apps/tauri?

Change the config entry to point to a concrete file, or use a glob pattern (e.g. `dir/**`) to include directory contents

tauri-apps/tauri · error

is not a file

Error message

{:?} is not a file

What it means

copy_file in tauri-build rejects sources that exist but are not regular files (e.g. directories, symlinks to dirs, or special files), because fs::copy only works on files. The offending path is embedded in the message.

Solutions

Change the config entry to point to a concrete file, or use a glob pattern (e.g. `dir/**`) to include directory contents
Replace symlink-to-directory sources with the real file path or copy semantics
Verify with `ls -la` / `Get-Item` that the path is a regular file

Example fix

// before (tauri.conf.json)
"resources": ["assets/configs"]  // is a directory
// after
"resources": ["assets/configs/**"]

Defensive patterns

Strategy: validation

Validate before calling

const isRegularFile = (p: string) => { try { return fs.statSync(p).isFile(); } catch { return false; } };
for (const r of cfg.bundle?.resources ?? []) {
  const p = resolve('src-tauri', r.replace(/[*].*$/, ''));
  if (fs.existsSync(p) && !isRegularFile(p) && !r.includes('*')) throw new Error(`Use a glob for directories: ${r}`);
}

Type guard

const isFile = (p: string): p is string => fs.statSync(p, { throwIfNoEntry: false })?.isFile() === true;

Try / catch

try {
  await copy(from, to);
} catch (e) {
  if (String(e).includes('is not a file')) throw new Error(`Point resources at files or use ** globs: ${e.message}`);
  throw e;
}

Prevention

Never point `resources` directly at a directory entry; use `dir/**`
Check symlinks resolve to regular files on the build machine
Lint tauri.conf.json paths in CI before building

When it happens

Trigger: A `bundle.resources` or frameworks entry in tauri.conf.json resolves to a directory or non-regular file when copy_file is called from copy_binaries/copy_resources/copy_frameworks.

Common situations: Pointing `resources` directly at a directory instead of using a glob or directory-copy semantics, a symlink to a directory, or a config path that accidentally matches a folder.

Understand the failure class

Background: "is not a compatible type" / "cannot merge" errors: when a value's type doesn't match what the library requires — this error's family across 65 libraries.

Related errors

AI-assisted analysis of tauri-apps/tauri@460ec35447 (2026-09-18). Data as JSON: /api/errors/f6e037c8d5fb6a90. Report an issue: GitHub.

Appendix: source

Thrown at crates/tauri-build/src/lib.rs:50

mod codegen;
mod manifest;
mod mobile;
mod static_vcruntime;

#[cfg(feature = "codegen")]
#[cfg_attr(docsrs, doc(cfg(feature = "codegen")))]
pub use codegen::context::CodegenContext;

pub use acl::{AppManifest, DefaultPermissionRule, InlinedPlugin};

fn copy_file(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
  let from = from.as_ref();
  let to = to.as_ref();
  if !from.exists() {
    return Err(anyhow::anyhow!("{:?} does not exist", from));
  }
  if !from.is_file() {
    return Err(anyhow::anyhow!("{:?} is not a file", from));
  }
  let dest_dir = to.parent().expect("No data in parent");
  fs::create_dir_all(dest_dir)?;
  fs::copy(from, to)?;
  Ok(())
}

fn copy_binaries(
  binaries: ResourcePaths,
  target_triple: &str,
  path: &Path,
  package_name: Option<&str>,
) -> Result<()> {
  for src in binaries {
    let src = src?;
    println!("cargo:rerun-if-changed={}", src.display());
    let file_name = src
      .file_name()

View on GitHub (pinned to 460ec35447)