What causes "'%{module_name}' (%{version}) requested; installation conflict" in puppetlabs/puppet?

Uninstall or remove the existing conflicting module from that modulepath directory first.

puppetlabs/puppet · error · Puppet::ModuleTool::Errors::InstallConflictError

'%{module_name}' (%{version}) requested; installation confli

Error message

'%{module_name}' (%{version}) requested; installation conflict

What it means

Installer raises Puppet::ModuleTool::InstallConflictError during the pre-install conflict check: a release in the resolved set maps to a short name that collides with a directory on the modulepath, but the installed module's forge name differs (i.e. a different author's module occupies that directory name). dependency is set when the colliding release is a transitive dependency rather than the requested module; directory and metadata of the existing module are included.

Source

Thrown at lib/puppet/module_tool/applications/installer.rb:211

              :unsatisfied => unsatisfied
            )
          end

          unless forced?
            # Check for module name conflicts.
            releases.each do |rel|
              installed_module = installed_modules_source.by_name[rel.name.split('-').last]
              next unless installed_module
              next if installed_module.has_metadata? && installed_module.forge_name.tr('/', '-') == rel.name

              if rel.name != name
                dependency = {
                  :name => rel.name,
                  :version => rel.version
                }
              end

              raise InstallConflictError,
                    :requested_module => name,
                    :requested_version => options[:version] || 'latest',
                    :dependency => dependency,
                    :directory => installed_module.path,
                    :metadata => installed_module.metadata
            end
          end

          Puppet.info _("Preparing to install ...")
          releases.each(&:prepare)

          Puppet.notice _('Installing -- do not interrupt ...')
          releases.each do |release|
            installed = installed_modules[release.name]
            if forced? || installed.nil?
              release.install(Pathname.new(results[:install_dir]))
            else
              release.install(Pathname.new(installed.mod.modulepath))

View on GitHub (pinned to e227c27540)

Solutions

Uninstall or remove the existing conflicting module from that modulepath directory first.
If both are legitimately needed, relocate one to a different modulepath entry prioritized for that environment.
Verify you are installing the intended author slug (check the error's :directory and :metadata to identify the incumbent).
Use --force only if you accept overwriting the other module's directory.

Example fix

# before
puppet module install acme-stdlib   # site-modules/stdlib holds puppetlabs-stdlib

# after
puppet module uninstall puppetlabs-stdlib && puppet module install acme-stdlib

Defensive patterns

Strategy: validation

Validate before calling

shortname = release_name.split('-').last
existing = environment.modules.find { |m| File.basename(m.path) == shortname }
if existing && existing.forge_name&.tr('/', '-') != release_name
  abort "directory #{shortname} already holds #{existing.forge_name}; uninstall first"
end

Try / catch

begin
  installer.run
rescue Puppet::ModuleTool::InstallConflictError => e
  # e.multiline_options carries :directory and :dependency
  handle_conflict(e.multiline_options[:directory])
end

Prevention

Standardize on a single source (Forge or internal fork) per module shortname.
Before installing a fork, uninstall the incumbent module or move it off the modulepath.
In CI, assert that modulepath shortnames map 1:1 to expected forge names.

When it happens

Trigger: Thrown at lib/puppet/module_tool/applications/installer.rb:211 when the library encounters an invalid state.

Common situations: Two teams maintaining same-named modules internally and from the Forge; installing a Forge fork under a different author slug over an existing module directory; leftover directories from renamed modules on shared modulepaths.

Related errors

AI-assisted analysis of puppetlabs/puppet@e227c27540 (2026-08-21). Data as JSON: /api/errors/9b9b2fe8c7ed8a13. Report an issue: GitHub.