Siddharth edited this page Jul 1, 2018 · 12 revisions

Setting up your development tools is important and may take time. Here you find the recommended setup for most tools as text editors, VCS, …


How to install and configure Merlin (for Emacs)

Install emacs using your package manager of choice.

Setup merlin from their documentation on emacs from scratch.

Try to open some *.ml file in Emacs, e.g.:

$ cd ~/git/coq
$ emacs toplevel/ &

Emacs display the following strange message:

The local variables list in ~/git/coq
contains values that may be safe (*).

Do you want to apply it?

Just press !, i.e. "apply the local variable list, and permanently mark these values (*) as safe."

Emacs then shows two windows:

  • one window that shows the contents of the "toplevel/" file
  • and the other window that shows greetings for new Emacs users.

If you do not want to see the second window next time you start Emacs, just check "Never show it again" and click on "Dismiss this startup screen."

The default key-bindings are described here:

If you want, you can customize them by replacing the following lines:

(define-key merlin-map (kbd "C-c C-x") 'merlin-error-next)
(define-key merlin-map (kbd "C-c C-l") 'merlin-locate)
(define-key merlin-map (kbd "C-c &") 'merlin-pop-stack)
(define-key merlin-map (kbd "C-c C-t") 'merlin-type-enclosing)

in the file ~/.opam/<opam version>/share/emacs/site-lisp/merlin.el with what you want. In the text below we assume that you changed the origin key-bindings in the following way:

(define-key merlin-map (kbd "C-n") 'merlin-error-next)
(define-key merlin-map (kbd "C-l") 'merlin-locate)
(define-key merlin-map (kbd "C-b") 'merlin-pop-stack)
(define-key merlin-map (kbd "C-t") 'merlin-type-enclosing)

Now, when you press Ctrl+L, Merlin will show the definition of the symbol in a separate window. If you prefer to jump to the definition within the same window, do this: <Alt+x> customize-group <ENTER> merlin <ENTER>

Merlin Locate In New Window

  Value Menu

    Never Open In New Window


    Set For Future Sessions

Testing Merlin Configuration:

$ cd ~/git/coq
$ emacs toplevel/ &
  • Go to the end of the file where you will see the "start" function.
  • Go to a line where init_toplevel function is called.
  • If you want to jump to the position where that function or datatype under the cursor is defined, press <Ctrl+L>
  • If you want to jump back, type: <Ctrl+B>
  • If you want to learn the type of the value at current cursor's position, type: <Ctrl+T>

Enabling auto-completion in emacs

Getting along with ocamldebug

The default ocamldebug key-bindings are described here.

If you want, you can customize them by putting the following commands:

Add to your ~/.emacs file:

(global-set-key (kbd "<f5>") 'ocamldebug-break)
(global-set-key (kbd "<f6>") 'ocamldebug-run)
(global-set-key (kbd "<f7>") 'ocamldebug-next)
(global-set-key (kbd "<f8>") 'ocamldebug-step)
(global-set-key (kbd "<f9>") 'ocamldebug-finish)
(global-set-key (kbd "<f10>") 'ocamldebug-print)
(global-set-key (kbd "<f12>") 'camldebug)

Let us try whether ocamldebug in Emacs works for us. (If necessary, re-)compile coqtop:

$ cd ~/git/coq
$ make -j4 coqide printers

open Emacs:

emacs toplevel/ &

and type:

<F12> ../bin/coqtop.byte <ENTER>  ../dev/ocamldebug-coq <ENTER>

As a result, a new window is open at the bottom where you should see:


i.e. an ocamldebug shell.

  1. Switch to the window that contains the file.
  2. Go to the end of the file.
  3. Find the definition of the start function.
  4. Go to the "let" keyword that is at the beginning of the first line.
  5. By pressing you set a breakpoint to the cursor's position.
  6. By pressing you start the bin/coqtop process.
  7. Then you can:
  • step over function calls:
  • step into function calls:
  • or finish execution of the current function until it returns: .

Other ocamldebug commands, can be typed to the window that holds the ocamldebug shell.

The points at which the execution of Ocaml program can stop are defined here:

Installing printers to ocamldebug

There is a pretty comprehensive set of printers defined for many common data types. You can load them by switching to the window holding the "ocamldebug" shell and typing:

(ocd) source "../dev/db"



autocmd FileType ocaml set expandtab

I'd love to know how to set up ocp-indent properly


Setup merlin by using the Merlin wiki page for vim from scratch.



Don't use origin for Coq's repo, but rather origin for your fork and upstream for the reference repo.

$ git remote -v
origin (fetch)
origin (push)
upstream (fetch)
upstream (push)


        pushdefault = origin

in your .gitconfig or your .git/config can ensure that you do not push to master or a stable branch by mistake (if you have commit rights).


To see the PRs add to your .git/config

[remote "upstream"]
	url =
        fetch = +refs/pull/*/head:refs/remotes/upstream/pr/*
Clone this wiki locally
You can’t perform that action at this time.
You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.
Press h to open a hovercard with more details.