Protobuf: protoc-gen-go hangs on mac OS X sierra

[brobits]

I have installed protobuf-3.0.0, built from source and installed on my system, from here

I have a working go compiler (go1.8 darwin/amd64)

I have run go get -u github.com/golang/protobuf/{proto,protoc-gen-go} and have obtained a protoc-gen-go binary in $GOPATH/bin

But, when I run proto-gen-go, even without parameters, execution hangs. protoc --go_out works just fine.

Has anyone run into this before? What could cause these hangs? Any shared dependencies which could cause this?

Edit

I have found this digging through docs:

provides a protoc-gen-go binary which protoc uses when invoked with the --go_out command-line flag. The --go_out flag tells the compiler where to write the Go source files. The compiler creates a single source file for each .proto file input.

Looks like this is just a case of misusing protoc-gen-go: it's intended to be invoked by protoc, not directly invoked. Would be nice to have an error if it's directly invoked rather than hanging, though.

[brobits]

It also appears dtrace is denied somewhere in the call stack (toward the end of my dtruss log):

open("/dev/urandom\0", 0x0, 0x0)         = 3 0
dtrace: error on enabled probe ID 2134 (ID 163: syscall::read:return): invalid kernel access in action #12 at DIF offset 92
close(0x3)       = 0 0
__pthread_sigmask(0x3, 0x0, 0x127B058)       = 0 0
bsdthread_register(0x104E7C0, 0x0, 0x0)      = -1 Err#22
dtrace: error on enabled probe ID 2132 (ID 165: syscall::write:return): invalid kernel access in action #12 at DIF offset 92
dtrace: error on enabled probe ID 2132 (ID 165: syscall::write:return): invalid kernel access in action #12 at DIF offset 92
dtrace: error on enabled probe ID 2132 (ID 165: syscall::write:return): invalid kernel access in action #12 at DIF offset 92
select(0x0, 0x0, 0x0, 0x0, 0x7FFF5FBFF378)       = 0 0
select(0x0, 0x0, 0x0, 0x0, 0x7FFF5FBFF378)       = 0 0
dtrace: error on enabled probe ID 2132 (ID 165: syscall::write:return): invalid kernel access in action #12 at DIF offset 92

[danlg]

@brobits how did you solve it ?

[larzen]

I had the same behavior. I have mac OS X sierra 10.12.6, go 1.8.3.

Basically, protoc program doesn't come with "go get -u github.com/golang/protobuf/protoc-gen-go".
In the README.md file it is stated to install the C++ implementation, and the link brings to some *zip file, which actually are the source code that must be compiled via the standard linux make chain: configure+make+make install (I already had Xcode installed).

Well, once compiled the protoc program and installed into PATH it works like a charm.

[cybrcodr]

Just fyi. The protobuf repo release page https://github.com/google/protobuf/releases does have links to zip files containing the pre-built protoc binary as well, e.g. protoc-3.3.0-osx-x86_64.zip. Ones with prefix protoc- contains pre-built binary for a specific platform.

[ClayShentrup]

brew install protoc

[brobits]

@danlg everyone else here is correct: while protoc-gen-go produces golang bindings for protocol buffers, it must be invoked by protoc. unfortunately, I don't think go get -u https://.../protoc-gen-go also provides the protoc binary, which must be directly invoked.

short answer: install protoc from source, then run protoc to generate Golang bindings. protoc will call into protoc-gen-go.

[puellanivis]

It should be noted: execution does not hang. It is instead blocking on reading from STDIN.

If you hit CTRL-D, to signal an EOF for STDIN, then execution will quit with a log message protoc-gen-go: error:no files to generate

[dsnet]

239 should help address accidental direct invocation of protoc-gen-go

[brobits]

@puellanivis good find, although I do wish it were better documented to prevent new users from scratching their heads when they invoke this directly from a shell and don't produce anything on STDIN, effectively thinking execution is hanging on something besides input.

[mayank-dixit]

brew install protoc

doesn't work.

[dsnet]

@mayank-dixit, that is a question for Homebrew package manager. This repository is only responsible for implementing protocol buffers for Go, and not how that code is distributed to other operating systems and platforms.

[ephemeral]

@mayank-dixit brew install protobuf

[wildneuro]

@mayank-dixit brew install protobuf

Thanks, worked!