Erlang webtool won't start

Question

Just wondering what is going on with my Erlang webtool. I am running Ubuntu 15.10 and I have checked that the erlang-webtool package is installed. However, when I try to run it I get the following:

    1> webtool:start().
    {error,
        {shutdown,
            {failed_to_start_child,
                {httpd_instance_sup,{127,0,0,1},8888,default},
                {shutdown,
                    {failed_to_start_child,
                        {httpd_manager,{127,0,0,1},8888,default},
                        {error,
                            {invalid_option,
                                {module_does_not_exist,mod_include}}}}}}}}

    =ERROR REPORT==== 7-Mar-2016::15:47:36 ===
    Failed initiating web server: 
    undefined
    {invalid_option,{module_does_not_exist,mod_include}}

My version of Erlang: Erlang/OTP 18 [erts-7.0] [source] [64-bit] [smp:8:8] [async-threads:10] [kernel-poll:false]

Any ideas? Thanks.

It looks like the httpd_manager module is not created correctly, if at all. — liam_g
See my edited answer. Manual fix or downgrade are your only options for using webtool. — Nathaniel Waisbrot

Nathaniel Waisbrot Nathaniel Waisbrot · Accepted Answer · 2016-03-08T15:34:14

Webtool appears to be broken in E/OTP 18. I see the same thing, and when I removed the mention of mod_include (which no longer exists) then webtool works.

For the quick fix: edit you webtool.erl by hand, remove the line that mentions mod_include, run erlc webtool.erl and then copy the resulting webtool.beam to the ebin directory, overwriting the existing file there.

For the proper fix, I've opened a PR: https://github.com/erlang/otp/pull/985

Edit: the verdict from the PR is that webtool is deprecated and will not be present at all in version 19. It's also not important enough to make an unplanned patch. If something important comes up (like a security-related bug) then the patch for that will probably include the fix to webtool. However, your best bets are either to downgrade to a lower version where webtool is not broken or to perform the manual fix I outlined above.

Erlang webtool won't start

1 Answers