In order to program with Golang in a more productive way, I just installed GoSublime for Sublime Text 2, as explained on their official GitHub repository:
Installation
Sublime Package Control allows you to easily install or remove GoSublime (and many other ST2 packages) from within the editor. It offers automatically updating packages as well so you no longer need to keep track of changes in GoSublime.
Install Sublime Package Control (if you haven't done so already) from http://wbond.net/sublime_packages/package_control .
Be sure to restart ST2 to complete the installation.
Bring up the command palette (default
ctrl+shift+porcmd+shift+p) and start typingPackage Control: Install Packagethen press return or click on that option to activate it. You will be presented with a new Quick Panel with the list of available packages. TypeGoSublimeand press return or on its entry to install GoSublime. If there is no entry for GoSublime, you most likely already have it installed.
Now, whenever I launch Sublime Text, I have the following error message:
MarGo: Missing required environment variables: GOPATH
See the `Quirks` section of USAGE.md for info
And a usage.md file opens automatically, with the following content:
Usage
=====
Note
----
* Unless otherwise mentioned, `super` replaces `ctrl` in key bindings on OS X.
* A mention of a (GO)PATH variable uses a colon(`:`) as the separator.
This is the PATH separator on Linux and OS X, Windows uses a semi-colon(`;`)
Settings
--------
You may customize GoSublime's behaviour by (creating and) customizing the file `Packages/User/GoSublime.sublime-settings`. Default settings are documented in `Packages/GoSublime/GoSublime.sublime-settings`. **WARNING** Do not edit any package file outside of `Packages/User/`, including files inside `Packages/GoSublime/` unless you have a reason to. These files are subject to being overwritten on update of the respective package and/or Sublime Text itself. You may also inadvertently prevent the respective package from being able to update via git etc.
Quirks
------
This section assumes you know what `GOPATH` is and how to set it. If you don't, please see http://golang.org/doc/code.html
In some systems, environment variables are not passed around as expected.
The result of which is that some commands e.g `go build` don't work
as the command cannot be found or `GOPATH` is not set. To get around this
the simplest thing to do is to set these variables in the settings file.
See the documentation for the `env` and/or `shell` setting, both documented in the default
settings file `Packages/User/GoSublime.sublime-settings`
Code Completion
---------------
Completion can be accessed by typing the (default) key combination `CTRL+[SPACE]` inside a Golang file.
Key Bindings
------------
By default, a number of key bindings are provided. They can be viewed by opening the command palette
and typing `GoSublime:` or via the key binding `ctrl+dot`,`ctrl+dot` (or `super+dot`,`super+dot` on OS X).
Wherever I refer to a key binding with `ctrl+` it is by default defined as `super+` on OS X unless stated otherwise.
Useful Key Bindings
-------------------
Often when commenting out a line, the immediate action following this is to move the cursor to the next line either to continue working or comment out the following line.
With this key binding, you can have the line commented out and the cursor automatically moved to the next line.
{ "keys": ["ctrl+/"], "command": "gs_comment_forward", "context": [{ "key": "selector", "operator": "equal", "operand": "source.go" }] },
Package Imports
---------------
Pressing `ctrl+dot`,`ctrl+p` will open the package list from which you can quickly import or delete a package import.
The usage is the same for both operations. If the package is already imported then it will appear near the top
and be marked as a *delete* operation, so in effect it is a toggle. If you want to edit the alias of a package e.g
a database driver: first import the package as normal and then press `ctrl+dot`,`ctrl+i` to quickly jump
the last imported package. Once edited you can return to where you were by pressing `ctrl+dot`,`ctrl+[`
Building, Testing and the Go command
------------------------------------
GoSublime comes with partial command/shell integration `9o`. For more information about 9o, see Packages/GoSublime/9o.md
or from within Sublime Text press `ctrl+9` or `super+9` and type `help`.
To run package tests you have 3 options.
* press `ctrl+dot`,`ctrl+t` to open the testing quick panel. This offers basic/common options such
as running all benchmark functions or running a single test function.
* inside a `_test.go` file, press `ctrl+shift` and left-click on the name of a Test, Benchmark or Example
function e.g. `TestAbc` to execute that function only.
* if the above options are too minimalistic or you would otherwise like to call `go test` with your own options,
open 9o by pressing `ctrl+9` where you have access to the `go` command.
In the case of building a package, 9o provides a replay command (see 9o.md for details) that will execute
the command if the pkg is a command pkg (package main) or run all tests if it's a normal pkg.
The replay command is bound to `ctrl+dot`,`ctrl+r` for easy access.
GoSublime provides an override for the Sublime Text build-system via `ctrl+b`. In the menu `Tools > Build System` it's named `GoSublime`.
`ctrl+b` is automatically handled by Sublime Text, so if you have another `Go` build system chosen, `ctrl+b`
will execute that instead. To access the `GoSublime` build system directly press `ctrl+dot`,`ctrl+b`.
This build system simply opens 9o and expand the last command. i.e. executes the 9o command `^1`.
Per-project Settings & Project-based GOPATH
-------------------------------------------
If you have a settings object called `GoSublime` in your project settings its values will override those
inside the `GoSublime.sublime-settings` file. As a side-effect you may set a specific GOPATH for a single
project.
`my-project.sublime-project`
{
"settings": {
"GoSublime": {
"env": {
"GOPATH": "$HOME/my-project"
}
}
},
"folders": []
}
If the only setting you use this functionality to change is the GOPATH, then you may be able to find
success by adding the string `$GS_GOPATH` to your global `GOPATH` setting e.g.
{
"env": { "GOPATH": "$HOME/go:$GS_GOPATH" }
}
`GS_GOPATH` is a pseudo-environment-variable. It's changed to match a possible GOPATH based on:
* the current working directory, e.g. `~/go/src/pkg` then `$GS_GOPATH` will be `~/go/`
* or the path the current `.go` file (or last activated `.go` file if the current file is not `.go`) e.g. if your file path is `/tmp/go/src/hello/main.go` then it will be `/tmp/go`
If you would like to use `GS_GOPATH` exclusively, you may set the option `use_gs_gopath` to true.
This automatically changes `GOPATH` to the value of `$GS_GOPATH` if `$GS_GOPATH` is not empty.
This allows you to e.g. automatically adapt `GOPATH` to your current project rather than
reverting to your normal `GOPATH`.
Lint/Syntax Check
-----------------
The source is continuously scanned for syntax errors. GoSublime will try to catch some common errors, like
forgetting to call flag.Parse (if this causes false positives, please file a bug report).
Apart from the highlighting in the view using a dot icon in the gutter and usually underlining the
first character of an error region. You are given an entry in the status bar in the form: `GsLint (N)`
where `N` is the number of errors found in that file. You can show the list of errors and navigate to
them by pressing `ctrl+dot`,`ctrl+e`. Errors for the current line are shown in the status bar.
Fmt
---
By default `ctrl+s` and `ctrl+shift+s` are overridden to fmt the the file before saving it. You may also
fmt a file without saving it by pressing `ctrl+dot`,`ctrl+f`
Godoc/Goto Definition
---------------------
To show the source and associated comments(documentation) of a variable press `ctrl+dot`,`ctrl+h` or
using the mouse `ctrl+shift+right-click`. This will show an output panel that presents the full
definition of the variable or function under the (first) cursor along with its comments.
To goto the definition instead, press `ctrl+dot`,`ctrl+g` or alternatively using the mouse `ctrl+shift+left-click`.
Declarations/Code Outline?
--------------------------
A very minimal form of code outline is provided. You can press `ctrl+dot`,`ctrl+d` to list all the declarations
in the current file.
New File
--------
Pressing `ctrl+dot`,`ctrl+n` will create a new Go file with the package declaration filled out.
It will try to be intelligent about it, so if the current directory contains package `mypkg` it will use that as the package name.
Misc. Helper Commands
---------------------
The following commands can be assigned key bindings to further improve your editing experience.
* gs_fmt - this command runs `gofmt` on the current buffer. Also available via the key binding `ctrl+dot`,`ctrl+f`.
* gs_fmt_save, gs_fmt_prompt_save_as - these commands will run the `go_fmt` followed by `save` or `prompt_save_as` - these are bound to `ctrl+s` and `ctrl+shift+s` respectively, by default.
* gs_comment_forward - this command will activate the `ctrl+/` commenting and move the cursor to the next line, allowing you to comment/uncomment multiple lines in sequence without breaking to move the cursor. You can replace the default behaviour by overriding it in your user key bindings (Preferences > Key Bindings - User) with `{ "keys": ["ctrl+/"], "command": "gs_comment_forward", "context": [{ "key": "selector", "operator": "equal", "operand": "source.go" }] }`
Some people seem to have had the same issue:
- Idiotproof instructions for MarGo: Missing required environment variables: GOPATH #310
- How come USAGE.MD opens everytime I open Sublime? #601
- gopath is set, but still show "MarGo: Missing required environment variables: GOPATH" #520
And the root cause of the problem could be that the GOPATH has not been defined.
Mine has been — export GOPATH=$HOME/code/go — and I am able to run Go (and .go files) on my computer.
Any idea of how this can be fixed?
