Chapter 4. Updating Erlang.mk

This chapter describes how to update the erlang.mk file in your repository.

4.1. Initial bootstrap

The first time you use Erlang.mk, it will bootstrap itself. It always uses the most recent version for this, so you don’t have to update after creating your project.

4.2. Updating

Later on though, updating becomes a necessity. Erlang.mk developers and contributors relentlessly improve the project and add new features; it would be a waste not to benefit from this.

That’s why updating Erlang.mk is so simple. All you need to do is to call make erlang-mk:

$ make erlang-mk
git clone https://github.com/ninenines/erlang.mk .erlang.mk.build
Cloning into '.erlang.mk.build'...
remote: Counting objects: 4035, done.
remote: Compressing objects: 100% (12/12), done.
remote: Total 4035 (delta 8), reused 4 (delta 4), pack-reused 4019
Receiving objects: 100% (4035/4035), 1.10 MiB | 1000.00 KiB/s, done.
Resolving deltas: 100% (2442/2442), done.
Checking connectivity... done.
if [ -f build.config ]; then cp build.config .erlang.mk.build; fi
cd .erlang.mk.build && make
make[1]: Entering directory '/home/essen/tmp/emkg/hello_joe/.erlang.mk.build'
awk 'FNR==1 && NR!=1{print ""}1' core/core.mk index/*.mk core/index.mk core/deps.mk plugins/protobuffs.mk core/erlc.mk core/docs.mk core/test.mk plugins/asciidoc.mk plugins/bootstrap.mk plugins/c_src.mk plugins/ci.mk plugins/ct.mk plugins/dialyzer.mk plugins/edoc.mk plugins/elvis.mk plugins/erlydtl.mk plugins/escript.mk plugins/eunit.mk plugins/relx.mk plugins/shell.mk plugins/triq.mk plugins/xref.mk plugins/cover.mk \
    | sed 's/^ERLANG_MK_VERSION = .*/ERLANG_MK_VERSION = 1.2.0-642-gccd2b9f/' > erlang.mk
make[1]: Leaving directory '/home/essen/tmp/emkg/hello_joe/.erlang.mk.build'
cp .erlang.mk.build/erlang.mk ./erlang.mk
rm -rf .erlang.mk.build

All that’s left to do is to commit the file!

Yep, it’s that easy.

4.3. Customizing the build

Erlang.mk allows you to customize which plugins are to be included in the erlang.mk file. You can do so by maintaining your own build.config file in your repository. Erlang.mk will automatically use it the next time you run make erlang-mk.

The build.config file contains the list of all files that will be built into the resulting erlang.mk file. You can start from the most recent version and customize to your needs.

You can also name the file differently or put it in a separate folder by modifying the value for ERLANG_MK_BUILD_CONFIG. You can also tell Erlang.mk to use a different temporary directory by changing the ERLANG_MK_BUILD_DIR variable.