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Golang 1.11 is here with modules and experimental WebAssembly port among other updates

The Golang team released Golang 1.11 rc1 two weeks back, and now the much awaited Golang 1.11 is here. Golang 1.11, released last Friday, comes with changes and improvements to the toolchain, runtime, libraries, preliminary support for “modules”, and experimental port to WebAssembly.

Golang is a modern programming language by Google, which was developed back in 2009 for application development. It’s simple syntax, concurrency support, and fast nature makes it one of the fastest growing languages in the software industry.

Let’s now explore the new features in Golang 1.11.


Go 1.11 adds an experimental port to WebAssembly ( js/wasm ) along with other changes.

Web Assembly

Go 1.11 adds new GOOS value “js” and GOARCH value “wasm” to  WebAssembly. Go files named *_js.go or *_wasm.go will now be ignored by Go tools except for times when GOOS/GOARCH values are being used.

The GOARCH name “wasm” is the official abbreviation of WebAssembly. The GOOS name “js” is due to the host environments like web browsers and Node.js, that executes the WebAssembly bytecode. Both of these host environments use JavaScript to embed WebAssembly.

RISC-V GOARCH values reserved

The main Go compiler does not provide support for the RISC-V architecture. Go 1.11 reserves the GOARCH values namely “riscv” and “riscv64” by Gccgo that supports RISC-V. This means that Go files named *_riscv.go will be ignored by Go tools except for cases when those GOOS/GOARCH values are being used.

Other changes

Go 1.11 now needs OpenBSD 6.2 or later, macOS 10.10 Yosemite or later, or Windows 7 or later. Any support for previous versions of these operating systems have been deprecated. It also offers support for the upcoming OpenBSD 6.4 release. With changes in the OpenBSD kernel, you won’t be able to run older versions of Go on OpenBSD 6.4.

With Go 1.11, the new environment variable settings have been added for 64-bit MIPS systems, namely, GOMIPS64=hardfloat (the default) and GOMIPS64=softfloat. These enable you to decide whether to use hardware instructions or software emulation for floating-point computations.

Go now uses a more efficient software floating point interface on soft float ARM systems (GOARM = 5). There is no need of a linux kernel configured with KUSER_HELPERS now on ARMv7.


There are also fixes made in Modules, packages, and debugging in Golang 1.11.


There’s now preliminary support added for a new experimental concept called “modules”, in Golang 1.11. This is an alternative to GOPATH with integrated support for versioning and package distribution. With the help of modules, developers are no longer limited to working inside GOPATH.

Package loading

There’s a new package, the golang.org/x/tools/go/packages that offers a simple API for locating and loading Go source code packages. It’s not yet part of the standard library but it effectively replaces the go/build package for many tasks.

Build cache requirement

Go 1.11 will be the last release which offers support for setting the environment variable GOCACHE=off ( to disable the build cache ), that was introduced in Go 1.10. The compiler toolchain now offers support for column information in line directives.

Improved debugging

The compiler in Go 1.11 now offers improved debugging for optimized binaries which includes variable location information, line numbers, and breakpoint locations. This makes it possible to debug binaries compiled without -N -l. There’s also experimental support added for calling Go functions from within a debugger.

Compiler Toolchain

Golang 1.11 offers support for column information in line directives. Also, a new package export data format is introduced which is transparent to end users, except for speeding up build times for large Go projects.


Runtime in Go 1.11 now makes use of a sparse heap layout. This ensures that there is no longer a limit to the size of the Go heap as the limit was 512GiB earlier. It also provides fixing of rare “address space conflict” failures in mixed Go/C binaries or binaries compiled with -race.

Library changes

There are various minor updates and changes to the core library in Golang 1.11.

  • Crypto: Crypto operations such as ecdsa.Sign, rsa.EncryptPKCS1v15 and rsa.GenerateKey, now randomly read an extra byte to ensure that tests don’t rely on internal behavior.
  • debug/elf: Constants such as ELFOSABI and EM have been added.
  • encoding/asn1: There is now support for “private” class annotations for fields in Marshal and Unmarshal.
  • image/gif: There is support for non-looping animated GIFs. They are denoted by having a LoopCount of -1.
  • math/big: With Golang 1.11, ModInverse now returns nil when g and n are not relatively prime.

Apart from these major updates, there are many other changes in Golang 1.11. To get more information, be sure to check the official Golang 1.11 release notes.

Read Next

Writing test functions in Golang [Tutorial]

How Concurrency and Parallelism works in Golang [Tutorial]

GoMobile: GoLang’s Foray into the Mobile World


Tech writer at the Packt Hub. Dreamer, book nerd, lover of scented candles, karaoke, and Gilmore Girls.


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