[go-nuts] Multiple GOPATH entries "hiding" each other

I suspect you have 2 package with the same name of "hello". First lives in
C:\GoProgramming2\gp2\src\hello directory. And second lives in
C:\GoProgramming\gp1\src\hello directory. It is impossible to refer to 2
different packages using single package path. I guess go command chooses to
use C:\GoProgramming2\gp2\src\hello package because you have listed
C:\GoProgramming2\gp2 first in your GOPATH, and will ignore your
C:\GoProgramming\gp1\src\hello directory.

Go command is trying hard to tell you should not do that - do not have 2
different packages with the same path.

Alex

Thanks for your note.

I do not have two packages with the same name - "hello". Albeit, all the
codes are under the customary 'main' packages in both the GOPATHS
configured.

However, even if the packages had the same name - "hello", why should it be
a problem since the two same-named packages are at two different project
directory structure!

-Nawazish


On Monday, October 6, 2014 1:22:58 AM UTC+5:30, Mohammad Nawazish Khan
wrote:

the codes are under the customary 'main' packages in both the GOPATHS
configured.

I think this is still not allowed. For example, if you run "go install
hello" command which of the two "projects" should get built:
C:\GoProgramming2\gp2\src\hello or C:\GoProgramming\gp1\src\hello? I think
your go command is confused. You have to help it.
be a problem since the two same-named packages are at two different project
directory structure!

Again, if you try to import either of your packages with `import "hello"`
somewhere in your code, which of your two packages should go command import?

Alex

Thanks for your note, Alex.

I see your point, however, in the same context (of multiple entries in the
GOPATH configuration) there is a situation where I want your elucidation:

If I am correct, the start of every GO code must be contained in 'main'
package inside 'main' function. And now if I have two application (implying
two entry points to two different applications), it would become obligatory
that they both have same 'main' package and function. Then in this
situation how would you configure the GOPATH, if it were you. I think I was
able to explain the situation.

-Nawazish

On Monday, October 6, 2014 1:22:58 AM UTC+5:30, Mohammad Nawazish Khan
wrote:

'main' package inside 'main' function.

If you're talking about Go program, then, yes, every Go program must have
"main" package that must have "main" function. And the program will start
with that "main" function.
different applications), it would become obligatory that they both have
same 'main' package and function.

They don't have "same" "main" package. Their "main" packages are unrelated
to each other. "main" package is special in Go as I have described above.
You also cannot import "main" package.
you. I think I was able to explain the situation.

I think your confusion is because you have made your GOPATH consist of 2
separate directories. Do not do that. Until you have good reason to have
it, and you have understanding of consequences of that decision. For
example, if you do GOPATH=C:\GoProgramming, then you can have 2 separate
programs in C:\GoProgramming\src\hello1 and C:\GoProgramming\src\hello2
directories. They can both be package "main", and therefore have "main"
function. But they will be independent of each other. You could build them
with correspondent commands:

go build hello1

and

go build hello2

Or you could install them with

go install hello1

and

go install hello2,

which will build them and copy executables into C:\GoProgramming\bin
directory. So after install commands you will have
C:\GoProgramming\bin\hello1.exe and C:\GoProgramming\bin\hello2.exe in
there.

You should read http://golang.org/doc/code.html It will explain everything
much better then I do.

Alex

Hi,

I appreciate your response and the time you are giving here.

Of course to build/install the source codes inside the GOPATH* separately*
will not mess things up. But initially I was trying to just say "go
install" than using the discreet form "go install hello1" and "go install
hello2".

Do you know any way how we can build and install multiple go programs in a
particular GOPATH by a generic "go install" command!

-Nawazish

On Monday, October 6, 2014 1:22:58 AM UTC+5:30, Mohammad Nawazish Khan
wrote:

Hi,

Multiple GOPATHs can be set by separating the entries by a suitable
Operating System dependent delimiter (a semicolon or a colon for Windows or
*nix based systems respectively). However, while running the "go install"
tool the gc compiler complains that, "go install: no install location for
C:\GoProgramming\gp1\src\hello: hidden by C:
\GoProgramming2\gp2\src\hello" . Earlier I had set the GOPATH as:

C:\>SET GOPATH=C:\GoProgramming2\gp2;C:\GoProgramming\gp1

Any explanation as to why the first entry in the GOPATH variable "hides"
the other one.

Sincerely,
Nawazish

Were you running 'go install .' from within
directory C:\GoProgramming\gp1\src\hello? That would explain it, since the
import path implied by . in that directory would be "hello", but importing
the path "hello" would yield a different package. The tool detects and
reports this ambiguity.

If it's not that, then please send more information.