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digitalmars.D.learn - Using D libraries with SDL. Error: "Cannot find module protobuf'

reply Nicol Farran Terra <nicolterramaze gmail.com> writes:
Here is my painpoint. I am trying to make a game engine using a 
combination of D and Swift, my two favorite programming 
languages. I chose D specifically for lower level features, like 
stuff for Vulkan and OpenGL as a 'learning experience'. That 
said, I wanted to keep my dependencies minimal, but I wanted to 
use protobuf for data serialization between the two.

I am not sure if this expected behavior, but importing this in my 
app.d does not work. I get an error about a missing import. I ran 
to my 'root' where my dub.sdl was, ran the build for the library 
which worked, but when I went back to my file, I get the same 
behavior. I am not sure what to make of this. I figured the 
library was out of date, but I didn't think much of it. I am 
actually not sure what to do since package managers are kind of 
voodoo magic to me.

To start, I am on Arch Linux and using the most recent D. Here is 
my dub.sdl. If this continues to give me issues, I might use a 
different library or serialization method...

name "protostate"
description "A minimal D application."
authors "Nicol Farran Terra"
copyright "Copyright © 2024, Nicol Farran Terra"
license "MIT"
dependency "protobuf" version="~>0.6.2"

I think this is expected behavior my first intuition is simply 
that 'this does not conform with modern D' or 'it is not found 
and I cannot install a package with dub'.
Both seem plausible to me. Any help would be appreciated.
Aug 23
next sibling parent reply IchorDev <zxinsworld gmail.com> writes:
On Saturday, 24 August 2024 at 00:24:12 UTC, Nicol Farran Terra 
wrote:

 I am not sure if this expected behavior, but importing this in 
 my app.d does not work. I get an error about a missing import.


You are importing `google.protobuf`, right?
Providing the app.d would be helpful, or at least a snippet of it 
with the import that’s giving you the ‘error’—presumably a 
compiler error?


 I ran to my 'root' where my dub.sdl was, ran the build for the 
 library which worked, but when I went back to my file, I get 
 the same behavior. I am not sure what to make of this.


Could you please elaborate about what this means? It’s a bit 
confusing.
Aug 23
parent reply Nicol Farran Terra <nicolterramaze gmail.com> writes:
On Saturday, 24 August 2024 at 06:35:50 UTC, IchorDev wrote:

 On Saturday, 24 August 2024 at 00:24:12 UTC, Nicol Farran Terra 
 wrote:

 I am not sure if this expected behavior, but importing this in 
 my app.d does not work. I get an error about a missing import.


 You are importing `google.protobuf`, right?
 Providing the app.d would be helpful, or at least a snippet of 
 it with the import that’s giving you the ‘error’—presumably a 
 compiler error?


 I ran to my 'root' where my dub.sdl was, ran the build for the 
 library which worked, but when I went back to my file, I get 
 the same behavior. I am not sure what to make of this.


 Could you please elaborate about what this means? It’s a bit 
 confusing.


No, I am just importing 'protobuf'. Also  the app is literally 
the base app when you run dub.init.
Here is a more exact error.
app.d(2): Error: unable to read module `protobuf`
app.d(2):        Expected 'google/protobuf.d' or 
'google/protobuf/package.d' in one of the following import paths:
import path[0] = /usr/include/dlang/dmd



Also, I tried with both google.protobuf and just protobuf. Same 
error. Although I do remember I got something interesting when 
trying to build a subproject of this one (it wasnt there for some 
reason)
Uhh, just 'root'. Where my dub.sdl is?
It is not overall project root, that is where my Package.swift 
files. It is in my Sources/source (yes because Dub does that by 
default + app.d) and in Sources is where my dub.sdl.
If you go to where my folder location is, and run dub build. It 
'works' fine if you run 'dub build'. Although only if you just 
import anything in std. If you try to import protobuf in the 
app.d, it just wont work. Here is that error.
source/app.d(2,8): Error: unable to read module `protobuf`
source/app.d(2,8):        Expected 'protobuf.d' or 
'protobuf/package.d' in one of the following import paths:
import path[0] = source/
import path[1] = 
../../../../.dub/packages/protobuf/0.6.2/protobuf/src/
import path[2] = /usr/include/dlang/dmd
Error /usr/bin/dmd failed with exit code 1.
Aug 24
parent reply IchorDev <zxinsworld gmail.com> writes:
On Saturday, 24 August 2024 at 11:34:18 UTC, Nicol Farran Terra 
wrote:

 You are importing `google.protobuf`, right?
 Providing the app.d would be helpful, or at least a snippet of 
 it with the import that’s giving you the ‘error’—presumably a 
 compiler error?


 No, I am just importing 'protobuf'.


Well, the package path is `google.protobuf`. If you import 
`protobuf` then you are telling the compiler to import something 
that does not exist, so naturally that gives you this error:


 If you try to import protobuf in the app.d, it just wont work. 
 Here is that error.
 source/app.d(2,8): Error: unable to read module `protobuf`
 source/app.d(2,8):        Expected 'protobuf.d' or 
 'protobuf/package.d' in one of the following import paths:
 import path[0] = source/
 import path[1] = 
 ../../../../.dub/packages/protobuf/0.6.2/protobuf/src/
 import path[2] = /usr/include/dlang/dmd
 Error /usr/bin/dmd failed with exit code 1.



 Also, I tried with both google.protobuf and just protobuf. Same 
 error.


So, how does this error look when you `import google.protobuf`?

dub is telling you the file path:
`../../../../.dub/packages/protobuf/0.6.2/protobuf/src/` ~ 
(`protobuf.d` or `protobuf/package.d`).
If you look, you will see that there’s no such file or folder, 
but [there should be a google folder & a protobuf folder inside 
it](https://github.com/dcarp/protobuf-d/blob/master/src/google/
rotobuf/package.d). The folder structure defines how the modules & packages are
named (i.e. `google/protobuf/package.d` => `import google.protobuf`), so in the
future you can check the folder structure if you have this issue anywhere else,
since sometimes dub packages just don’t say how they should be imported.


 Also the app is literally the base app when you run dub.init.
 Here is a more exact error.
 app.d(2): Error: unable to read module `protobuf`
 app.d(2):        Expected 'google/protobuf.d' or 
 'google/protobuf/package.d' in one of the following import 
 paths:
 import path[0] = /usr/include/dlang/dmd


Are you just running dmd on `app.d` from inside `source` this 
time? If not then why are all of your project’s import paths 
missing??


 Although I do remember I got something interesting when trying 
 to build a subproject of this one (it wasnt there for some 
 reason)


Did you try `dub build protobuf:protoc-gen-d`?


 Uhh, just 'root'. Where my dub.sdl is?


Yes, that’s the root directory of your dub package.
Aug 24
parent reply Nicol Farran Terra <nicolterramaze gmail.com> writes:
On Saturday, 24 August 2024 at 12:11:03 UTC, IchorDev wrote:

 snip



Okay, yeah now I see my problem sort of. So now it at least 
builds, but it wont compile with dmd app.d.
Says basically the same thing before where it cannot find the 
module. Maybe I am supposed to link it? I am so used to doing 
single file projects, I just did dmd app.d to see if it would 
work.

But yes, good news is in dub.sdl root, it builds. So I think I am 
good? Maybe I am just missing something in the compiler use lol. 
I think I can assume if I can build with my SDL at my dub.sdl 
root, it should be fine. I think. Idk
Aug 24
parent reply IchorDev <zxinsworld gmail.com> writes:
On Saturday, 24 August 2024 at 12:24:04 UTC, Nicol Farran Terra 
wrote:

 On Saturday, 24 August 2024 at 12:11:03 UTC, IchorDev wrote:

 snip



 Okay, yeah now I see my problem sort of. So now it at least 
 builds, but it wont compile with dmd app.d.
 Says basically the same thing before where it cannot find the 
 module. Maybe I am supposed to link it? I am so used to doing 
 single file projects, I just did dmd app.d to see if it would 
 work.

 But yes, good news is in dub.sdl root, it builds. So I think I 
 am good? Maybe I am just missing something in the compiler use 
 lol. I think I can assume if I can build with my SDL at my 
 dub.sdl root, it should be fine. I think. Idk


If you build directly with dmd you will have to specify 
everything you build against manually, including your 
dependencies’ import directories. However, there’s no reason to 
do that since dub does this for you (and caches builds too). If 
you want to know what commands dub is running to build your 
project then you can use `dub -v --force`.
Aug 24
parent reply Nicol Farran Terra <nicolterramaze gmail.com> writes:
On Saturday, 24 August 2024 at 12:29:41 UTC, IchorDev wrote:

 On Saturday, 24 August 2024 at 12:24:04 UTC, Nicol Farran Terra 
 wrote:

 On Saturday, 24 August 2024 at 12:11:03 UTC, IchorDev wrote:

 snip


 snip2




That is....very helpful. So sort of like Swift, running the 
'build' command will just go through my source tree and just make 
sure everything links + builds for compile or am I missing 
something?
So basically, unless I want to use the compiler -f flag, I should 
probably just use dub build going forward to see if my work 
compiles.
Aug 24
parent IchorDev <zxinsworld gmail.com> writes:
On Saturday, 24 August 2024 at 12:35:03 UTC, Nicol Farran Terra 
wrote:

 On Saturday, 24 August 2024 at 12:29:41 UTC, IchorDev wrote:

 On Saturday, 24 August 2024 at 12:24:04 UTC, Nicol Farran 
 Terra wrote:

 On Saturday, 24 August 2024 at 12:11:03 UTC, IchorDev wrote:

 snip


 snip2




 That is....very helpful. So sort of like Swift, running the 
 'build' command will just go through my source tree and just 
 make sure everything links + builds for compile or am I missing 
 something?


You’re spot on.


 So basically, unless I want to use the compiler -f flag, I 
 should probably just use dub build going forward to see if my 
 work compiles.


You could add `dflags "-f"` to your dub.sdl if you want the 
compiler to be passed `-f`: 
https://dub.pm/dub-reference/build_settings/#dflags
Keep in mind that some flags are compiler-specific, so if you 
want to try LDC2 or GDC you might need to create 
compiler-specific variations:
```sdl
dflags "-example" platform="dmd"
dflags "-example" platform="ldc"
dflags "--example" platform="gdc"
```

Good luck!
Aug 24
prev sibling parent Serg Gini <kornburn yandex.ru> writes:
On Saturday, 24 August 2024 at 00:24:12 UTC, Nicol Farran Terra 
wrote:

 wanted to use protobuf for data serialization between the two.


Maybe consider to use msgpack instead of protobuf

This version of protobuf is broken for modern versions of D 
compilers
Aug 25