; set to "help" to see the available options
-O, --optimize={0,1,2,3} Set the optimization level (default level is 2 if unspecified or 3 if used without a level)
```
imho: the command line parameters can be also important.
#2.
The [julia/.github/ISSUE\_TEMPLATE.md](https://github.com/JuliaLang/julia/blob/master/.github/ISSUE_TEMPLATE.md) has an other important advice:
- creating **a minimal reproducible example**
---
### Author:  [@ImreSamu](https://discourse.julialang.org/u/ImreSamu)
#### Post date: [November 25, 2018, 1:42pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/6 "2018-11-25T13:42:29Z")
> [@foobar\_lv2](#):
>
> either @ImreSamu is unwise enough to always run as root, or wise enough to have noticed this pitfall)
🙂
**I agree, Privacy is important.**
I am a big fan of containerized development with docker.
and the [official julia docker images](https://hub.docker.com/r/library/julia/) - is configured for `ṙoot user`.
With docker - I can test and use multiple julia versions, and easier to create **a minimal reproducible example**
**Julia 1.0.2**
```julia
# docker run -it julia:1.0.2 bash -c 'id && julia'
uid=0(root) gid=0(root) groups=0(root)
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.0.2 (2018-11-08)
_/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia>
```
**Julia 0.7**
```julia
# docker run -it julia:0.7.0-stretch bash -c 'id && julia'
uid=0(root) gid=0(root) groups=0(root)
_
_ _ _(_)_ | A fresh approach to technical computing
(_) | (_) (_) | Documentation: https://docs.julialang.org
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 0.7.0 (2018-08-08 06:46 UTC)
_/ |\ __'_|_|_|\__'_| | Official http://julialang.org/ release
|__/ | x86_64-pc-linux-gnu
julia>
```
---
### Author:  [@foobar\_lv2](https://discourse.julialang.org/u/foobar_lv2)
#### Post date: [November 25, 2018, 2:56pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/7 "2018-11-25T14:56:33Z")
> [@ImreSamu](#):
>
> > either @ImreSamu is unwise enough to always run as root, or wise enough to have noticed this pitfall
>
> the [official julia docker images](https://hub.docker.com/r/library/julia/) - is configured for `ṙoot user` .
The third way 🙂
---
### Author:  [@johnh](https://discourse.julialang.org/u/johnh)
#### Post date: [November 25, 2018, 3:25pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/8 "2018-11-25T15:25:50Z")
Going wildly off topic, my preferred containerisation framework is Singularity.
They have given a great deal of thought to security.
[https://singularity.lbl.gov/docs-security](https://singularity.lbl.gov/docs-security)
[https://www.sylabs.io/guides/3.0/user-guide/security\_options.html](https://www.sylabs.io/guides/3.0/user-guide/security_options.html)
---
### Author:  [@bennedich](https://discourse.julialang.org/u/bennedich)
#### Post date: [November 25, 2018, 8:52pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/9 "2018-11-25T20:52:27Z")
My two cents: I think we should focus on having people create a proper **minimum reproducible example**. That’s by far the most important IMO. I think [this post](https://discourse.julialang.org/t/psa-make-it-easier-to-help-you/14757) covers it quite well already.
I actually think a long post, including all sorts of details that may or may not be relevant to the problem, can deter people from responding. And personally, I find forums that require me to submit all kinds of system details and logs before even looking at my question (when I know it’s irrelevant) quite frustrating.
As for “Julia is slow” questions, I rarely find that they’re stated in absolute terms, rather they tend to be compared to another implementation _on the same system_, in which case details such as CPU speed and RAM are often not relevant.
[Here’s an example](https://discourse.julialang.org/t/matrix-exponential-slower-in-julia-0-7-1-0/14762) of a “Julia is slow” question which I think is fully sufficient.
---
### Author:  [@peter.derijk](https://discourse.julialang.org/u/peter.derijk)
#### Post date: [November 30, 2018, 2:27pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/10 "2018-11-30T14:27:20Z")
I agree completely that having a reproducible example is the most important, and that these are usually comparative anyway, making things like CPU and storage often irrelevant. I don’t see why people would feel “victimized” by being asked for them when they might be relevant. Requiring the a priori submission of all kinds of data that the user knows are irrelevant is more frustrating imo. For a FAQ, I would ask for:
- a reproducible example
- version info (small and probably relevant)
- read the performance tips (but do not get enoyed if the poster missed some 🙂
---
### Author:  [@johnh](https://discourse.julialang.org/u/johnh)
#### Post date: [November 30, 2018, 7:23pm UTC](https://discourse.julialang.org/t/julia-is-slow-questions-how-to-request-information/17969/11 "2018-11-30T19:23:48Z")
@peter.derijk I think you make a lot of sense here.
Indeed we should ask for a reproducible sample and the version information.