junegunn/fzf · error

failed to start pprof profiles: %s

Error message

failed to start pprof profiles: %s

What it means

fzf failed to start the pprof CPU/blockprofileng profiles requested via --profile-cpu, --profile-mem, or --profile-block. opts.initProfiling() returned an error (typically a file creation/open failure for a profile path), and options.go:3890 wraps it as 'failed to start pprof profiles: <cause>'.

Source

Thrown at src/options.go:3890

			}
			opts.MinHeight += borderLines(borderShape) + opts.HeaderLines
		}
		if len(opts.Preview.command) > 0 && (opts.Preview.position == posUp || opts.Preview.position == posDown) && opts.Preview.Visible() && opts.Preview.position == posUp {
			borderShape := opts.Preview.border
			if opts.Preview.border == tui.BorderLine {
				borderShape = tui.BorderTop
			}
			opts.MinHeight += borderLines(borderShape) + 10
		}
		for _, s := range []sizeSpec{opts.Margin[0], opts.Margin[2], opts.Padding[0], opts.Padding[2]} {
			if !s.percent {
				opts.MinHeight += int(s.size)
			}
		}
	}

	if err := opts.initProfiling(); err != nil {
		return errors.New("failed to start pprof profiles: " + err.Error())
	}

	algo.Init(opts.Scheme)

	return nil
}

func parseShellWords(str string) ([]string, error) {
	parser := shellwords.NewParser()
	parser.ParseComment = true
	return parser.Parse(str)
}

// ParseOptions parses command-line options
func ParseOptions(useDefaults bool, args []string) (*Options, error) {
	opts := defaultOptions()
	index := 0

View on GitHub (pinned to bd4efa277b)

Solutions

1. Check the wrapped cause: 'no such file or directory' means the parent directory must be created; 'permission denied' means fixing ownership/permissions
2. Use an absolute path in a writable directory, e.g. --profile-cpu=/tmp/fzf.pprof
3. Ensure the path names a file (not a directory) and the disk is not full
4. Remove stale root-owned profile files from earlier sudo runs

Example fix

# before
fzf --profile-cpu=/var/log/fzf/cpu.pprof
# after
mkdir -p /tmp/fzf-prof && fzf --profile-cpu=/tmp/fzf-prof/cpu.pprof

# Shell: ensure the profile directory is writable before launch
prof_dir=/tmp/fzf-prof
mkdir -p "$prof_dir" && [ -w "$prof_dir" ] || { echo "cannot write $prof_dir" >&2; exit 1; }
exec fzf --profile-cpu="$prof_dir/cpu.pprof"

In Go, capture exec.ExitError stderr; if it starts with 'failed to start pprof profiles:', surface the wrapped cause (usually 'no such file or directory' or 'permission denied') and fail fast — retrying will not help until the path is fixed.

When it happens

Trigger: Passing --profile-cpu (or mem/block) pointing to a path in a nonexistent directory, a path without write permission, or a directory instead of a file: os.Create inside initProfiling fails and the wrapped error is returned during option finalization.

Common situations: Profiling in containers or restricted environments where the target directory is read-only; relative profile paths resolved from an unexpected working directory; disk full; leftover root-owned profile files from a previous sudo run.

Related errors

• could not create CPU profile: %w
• could not create MEM profile: %w
• could not create BLOCK profile: %w
• could not create MUTEX profile: %w
• no directory specified

AI-assisted analysis of junegunn/fzf@bd4efa277b (2026-08-15). Data as JSON: /api/errors/1da60f73a96793e1. Report an issue: GitHub.