jdx/mise · error · RuntimeError

inreplace: #{before.inspect} not found

Error message

inreplace: #{before.inspect} not found

What it means

This error comes from a small inreplace helper (a port of Homebrew's `inreplace` utility) that wraps `String#gsub!`. When `gsub!` finds no match it returns nil, and unless auditing is disabled (`audit_result = false`), the helper raises 'inreplace: <pattern> not found' to signal that the expected text was not present in the file/string being edited. It exists so silent no-op replacements are caught instead of corrupting files unnoticed.

Source

Thrown at src/system/packages/brew/shim.rb:877

  def time = Time.now

  def post_install; end

  # unknown instance helpers: fail loudly
  def method_missing(name, *args, &block)
    shim_unsupported!("#{name} (install-time helper)")
  end

  def respond_to_missing?(_name, _include_private = false) = true

  class InreplaceText
    attr_reader :text

    def initialize(text) = @text = text

    def gsub!(before, after, audit_result = true)
      result = @text.gsub!(before, after.to_s)
      raise "inreplace: #{before.inspect} not found" if result.nil? && audit_result
      result
    end

    def sub!(before, after)
      @text.sub!(before, after.to_s)
    end

    def change_make_var!(flag, new_value)
      replaced = @text.gsub!(/^#{Regexp.escape(flag)}[ \t]*[\\?\\+\\:]?=[ \t]*((?:.*\\\n)*.*)$/, "#{flag}=#{new_value}")
      opoo "change_make_var! #{flag} did nothing" if replaced.nil?
      replaced
    end
  end
end

def main
  load MISE_BREW_FORMULA_FILE.to_s
  klass = Formula.instance_variable_get(:@formula_subclass)

View on GitHub (pinned to afd2eddd3a)

Solutions

  1. Print/inspect the actual file content and update the `before` pattern so it matches current text
  2. Confirm the pattern is being applied to the right file/version (pin or update the tool version the pattern was written for)
  3. Make the regex more permissive (e.g. allow optional whitespace or alternative spellings)
  4. If the replacement is genuinely optional, pass `audit_result = false` so a missing match does not raise
  5. Report/update the shim pattern for the new upstream version

Example fix

# before
s.gsub!('prefix=/usr/local', "prefix=#{HOMEBREW_PREFIX}")
# after
raise "unexpected Makefile layout" unless s.text.include?('prefix=')
s.gsub!(/^prefix\s*=.*$/, "prefix=#{HOMEBREW_PREFIX}")
Defensive patterns

Strategy: validation

Validate before calling

raise 'pattern missing from file' unless text.include?(pattern) # check before calling gsub!
text.gsub!(pattern, replacement)

Try / catch

begin
  s.gsub!(pattern, replacement)
rescue RuntimeError => e
  raise e unless e.message.start_with?('inreplace:')
  # handle no-op replacement: log and continue or fall back
end

Prevention

When it happens

Trigger: Calling `gsub!(before, after)` on the helper with a `before` pattern that does not match any substring of `@text`; the pattern may be a literal string, regex, or a dynamic pattern built from a version string that changed upstream.

Common situations: Patching formulas/casks during brew-based installs where upstream source changed a line (version bump renamed a flag, path, or shebang); regex built from an interpolated version that no longer appears; running against a newer upstream release before the shim pattern is updated.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/ba6843212c44667e. Report an issue: GitHub.