Building Syncthing¶
Note
You probably only need to go through the build process if you are going to do development on Syncthing or if you need to do a special packaging of it. For all other purposes we recommend using the official binary releases instead.
Note
Syncthing uses Go modules, which is a fairly new development in the Go ecosystem. You can find more information about modules here. If you are not a seasoned Go developer you can just go with the flow as this is the new thing.
Prerequisites¶
The latest stable version of Go. Earlier releases may work, but we recommend always using the latest stable version. At the time of writing this is Go 1.17.
Git
If you want to build Debian packages FPM is required. See FPM’s installation information.
To build Windows executables, installing goversioninfo is recommended in order to add file properties and icon to the compiled binaries.
Building Android binaries requires Android NDK.
If you’re not already a Go developer, the easiest way to get going is to download the latest version of Go as instructed in https://golang.org/doc/install.
Note
Because Syncthing uses Go modules you do not need to set or care about “GOPATH”.
However, the GOPATH still defaults to ~/go
and you’d be best to not
put your Syncthing source in there, for now.
Building (Unix)¶
Install the prerequisites.
Open a terminal.
Run the commands below.
# This should output "go version go1.17" or higher.
$ go version
# Pick a place for your Syncthing source.
$ mkdir -p ~/dev
$ cd ~/dev
# Grab the code.
$ git clone https://github.com/syncthing/syncthing.git
# Now we have the source. Time to build!
$ cd syncthing
# You should be inside ~/dev/syncthing right now.
$ go run build.go
Unless something goes wrong, you will have a syncthing
binary built
and ready in ~/dev/syncthing/bin
.
Building (Windows)¶
Install the prerequisites.
Open a
cmd
Window.Run the commands below.
# This should output "go version go1.17" or higher.
> go version
# Pick a place for your Syncthing source.
> md "%USERPROFILE%\dev"
> cd "%USERPROFILE%\dev"
# Grab the code.
> git clone https://github.com/syncthing/syncthing.git
# Now we have the source. Time to build!
> cd syncthing
> go run build.go
Unless something goes wrong, you will have a syncthing.exe
binary
built and ready in %USERPROFILE%\dev\syncthing\bin
.
Subcommands and Options¶
The following build.go
subcommands and options exist.
go run build.go install
Installs binaries in
./bin
(default command, this is what happens when build.go is run without any commands or parameters).go run build.go build
Builds just the named target, or
syncthing
by default, to the current directory. Use this when cross compiling, with parameters for what to cross compile to:go run build.go -goos linux -goarch 386 build
.go run build.go test
Runs the tests.
go run build.go deb
Creates a Debian package in the current directory. Requires FPM and a Unixy build.
go run build.go tar
Creates a Syncthing tar.gz dist file in the current directory. Assumes a Unixy build.
go run build.go zip
Creates a Syncthing zip dist file in the current directory. Assumes a Windows build.
The options -no-upgrade
, -goos
and -goarch
can be given to
influence build
, tar
and zip
. Examples:
go run build.go -goos linux -goarch 386 tar
Builds a tar.gz distribution of Syncthing for linux-386.
go run build.go -goos windows -no-upgrade zip
Builds a zip distribution of Syncthing for Windows (current architecture) with upgrading disabled.
Version Tagging¶
The binaries are “tagged” with a version derived from the current Git commit
(or the RELEASE
file, see below) and the current username and hostname.
The username and hostname can be overridden by the BUILD_USER
and
BUILD_HOST
environment variables, for example:
$ BUILD_USER=builder BUILD_HOST=buildhost.local go run build.go
$ ./bin/syncthing --version
syncthing v1.8.0 ... builder@buildhost.local 2020-07-30 11:49:14 UTC
In addition the timestamp (by default taken from the current Git commit) can
be overridden by the SOURCE_DATE_EPOCH
variable, in Unix epoch seconds.
Building without Git¶
Syncthing can be built perfectly fine from a source tarball of course.
If the tarball is from our build server it contains a file called
RELEASE
that informs the build system of the version being
built. If you’re building from a different source package, for example
one automatically generated by GitHub, you must instead pass the
-version
flag to build.go
.
If you are building something that will be installed as a package
(Debian, RPM, …) you almost certainly want to use -no-upgrade
as
well to prevent the built in upgrade system from being activated.
go run build.go -version v0.10.26 -no-upgrade tar
Builds a tar.gz distribution of Syncthing for the current OS/arch, tagged as
v0.10.26
, with upgrades disabled.