docs: add troubleshooting guide about package not being found

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>
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Mark Sagi-Kazar 2021-02-15 07:43:37 +01:00 committed by Márk Sági-Kazár
parent d10c856f6c
commit e66f940bcc

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@ -860,3 +860,21 @@ You can vote for case sensitivity by filling out this feedback form: https://for
### Unmarshaling doesn't work
The most common reason for this issue is improper use of struct tags (eg. `yaml` or `json`). Viper uses [github.com/mitchellh/mapstructure](https://github.com/mitchellh/mapstructure) under the hood for unmarshaling values which uses `mapstructure` tags by default. Please refer to the library's documentation for using other struct tags.
### Cannot find package
Viper installation seems to fail a lot lately with the following (or a similar) error:
```
cannot find package "github.com/hashicorp/hcl/tree/hcl1" in any of:
/usr/local/Cellar/go/1.15.7_1/libexec/src/github.com/hashicorp/hcl/tree/hcl1 (from $GOROOT)
/Users/user/go/src/github.com/hashicorp/hcl/tree/hcl1 (from $GOPATH)
```
As the error message suggests, Go tries to look up dependencies in `GOPATH` mode (as it's commonly called) from the `GOPATH`.
Viper opted to use [Go Modules](https://github.com/golang/go/wiki/Modules) to manage its dependencies. While in many cases the two methods are interchangeable, once a dependency releases new (major) versions, `GOPATH` mode is no longer able to decide which version to use, so it'll either use one that's already present or pick a version (usually the `master` branch).
The solution is easy: switch to using Go Modules.
Please refer to the [wiki](https://github.com/golang/go/wiki/Modules) on how to do that.
**tl;dr* `export GO111MODULE=on`