zed-industries/zed · error

pylsp installation was incomplete

Error message

pylsp installation was incomplete

What it means

Raised in pylsp fetch_server_binary(): the required pylsp-mypy plugin install is verified after the main install and failed, so the venv's pylsp installation is incomplete and the binary should not be used.

Source

Thrown at crates/languages/src/python.rs:2016

                    .output()
                    .await?
                    .status
                    .success(),
                "python-lsp-server[all] installation failed"
            );
            ensure!(
                util::command::new_command(pip_path)
                    .arg("install")
                    .arg("pylsp-mypy")
                    .arg("--upgrade")
                    .output()
                    .await?
                    .status
                    .success(),
                "pylsp-mypy installation failed"
            );
            let pylsp = venv.join(BINARY_DIR).join("pylsp");
            ensure!(
                delegate.which(pylsp.as_os_str()).await.is_some(),
                "pylsp installation was incomplete"
            );
            Ok(LanguageServerBinary {
                path: pylsp,
                env: None,
                arguments: vec![],
            })
        }
    }

    async fn cached_server_binary(
        &self,
        _: PathBuf,
        delegate: &dyn LspAdapterDelegate,
    ) -> Option<LanguageServerBinary> {
        let venv = self.base_venv(delegate).await.ok()?;
        let pylsp = venv.join(BINARY_DIR).join("pylsp");

View on GitHub (pinned to f4178619ac)

Solutions

1. Delete the venv and let Zed re-provision it from scratch
2. Check the venv bin directory for the expected entrypoint name/platform quirks
3. Verify pip reported success for the same environment Zed inspects

When it happens

Trigger: Thrown at crates/languages/src/python.rs:2016 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/ca32a8c0f5ea80e6. Report an issue: GitHub.