Re: Scripting guix in guile (Konrad Hinsen)

[Gary Johnson]

Hi Konrad,

Just in case you hadn't thought of this yet, you can ensure that
/usr/bin/env exists on any Guix system by consing the following entry
onto the list of services under your operating-system definition.

(extra-special-file "/usr/bin/env" (file-append coreutils "/bin/env"))

Then your scripts could just use #!/usr/bin/env and work natively
on GuixSD or a foreign distribution.

Here's what the services entry looks like in my operating-system
definition as an example:

(services (cons* (extra-special-file "/usr/bin/env" (file-append coreutils 
"/bin/env"))
                 (postgresql-service #:extension-packages (list postgis))
                 (service bitlbee-service-type)
                 (service docker-service-type)
                 %desktop-services))

It's one extra step to explain in your tutorial, but if any of your
students are already curious/brave enough to have installed GuixSD, they
should be capable of adding that one line to the config.scm file
(containing the operating-system definition) that they already had to
create at OS install time. Then they just run `guix system reconfigure
config.scm`, and they've got /usr/bin/env added to their system. No
reboot. No delay. Just on with the show!

YMMV,
  Gary


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> Today's Topics:
>
>    1. Report on environment variable issues (Tirifto)
>    2. Re: rust:cargo (libcurl) vs. CURL_CA_BUNDLE (David Loyall)
>    3. Re: adding environment variables to /etc/config.scm
>       (Jonathan Lane)
>    4. Re: Report on environment variable issues (Mikhail Kryshen)
>    5. Re: Scripting guix in guile (Konrad Hinsen)
>    6. Re: Help defining a trivial package. (Pierre-Henry F.)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 3 Sep 2019 21:25:50 +0200
> From: Tirifto <address@hidden>
> To: address@hidden
> Subject: Report on environment variable issues
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=UTF-8
>
> Hello!
>
> I am running Guix on Parabola GNU+Linux-libre (a libre derivative of
> Arch Linux), and have had issues with environment variables in two
> instances. I'm not asking for help, but I'm not sure if this is
> appropriate for the bug list, either, so here we go.
>
> Firstly, when running GNOME Shell (native on Parabola), I tried
> integrating it with Guix, so that applications installed with Guix
> would be visible to GNOME Shell. I tried doing this by extending the
> environment variable ‘$XDG_DATA_DIRS’, which is empty by default,
> but that made GNOME Shell crash on login.
>
> After some investigation, it turned out that GNOME Shell falls back on
> a certain default value when the variable is empty, which already
> contains paths that GNOME Shell needs to function properly. So when the
> user extends the existing value of ‘$XDG_DATA_DIRS’ with another path,
> the variable is no longer empty, so GNOME Shell never gets to fall back
> to the paths it actually needs, and crashes instead.
>
> The solution was to manually add the paths to the extension/definition.
> I used ‘/usr/local/share:/usr/share’; not sure if that's all there was
> to it, but GNOME Shell could work with it. See also this Parabola bug:
>
> https://labs.parabola.nu/issues/2388
>
> Secondly, I find that the program ‘youtube-dl’ (native on Parabola)
> doesn't work properly when I define environment variables for SSL
> Certificates as advised by the Guix manual, like so:
>
>   export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
>   export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certif\
>   icates.crt"
>
> youtube-dl then complains about being unable to get local issuer
> certificates. On the other hand, when the variables are undefined, Guix
> complains about certificates, for a change (e.g. when running ‘guix
> weather’).
>
> My current solution is to comment the variables out in my ~/.profile,
> and only export them in the terminal when I'm about to use Guix.
>
> I don't know if these are reliably reproducible, and whether they
> should be fixed somewhere, or just better documented, but I hope the
> info can help!
>
> Best wishes
> // Tirifto
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 3 Sep 2019 19:16:48 -0500
> From: David Loyall <address@hidden>
> To: Ludovic Courtès <address@hidden>
> Cc: address@hidden
> Subject: Re: rust:cargo (libcurl) vs. CURL_CA_BUNDLE
> Message-ID:
>       <CA+4fW6mVX0hte+4SjDbgBNrr=address@hidden>
> Content-Type: text/plain; charset="UTF-8"
>
>> This was discussed recently on IRC:
>>   http://logs.guix.gnu.org/guix/2019-08-29.log#102010
>> Unfortunately we didn’t reach a conclusion.
>
> Ok, thank you.  Unfortunately that user's pastebins expired so I was
> not able to compare with my own `ltrace` output.
>
>> The ‘ltrace -e getenv’ trick I gave might give us
>> clues about relevant environment variables.
>
> Ok, let's see:
>
>     sebboh@geeks ~$ ltrace -e getenv cargo -vv install rustfmt-nightly
>     libcrypto.so.1.0.0->getenv("SSL_CERT_FILE")
>                                                         =
> "/home/sebboh/.guix-profile/etc/s"...
>     libcrypto.so.1.0.0->getenv("SSL_CERT_DIR")
>                                                         =
> "/home/sebboh/.guix-profile/etc/s"...
>         Updating crates.io index
>     libcurl.so.4->getenv("no_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("NO_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("https_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("HTTPS_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("all_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("ALL_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("no_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("NO_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("http_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("all_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("ALL_PROXY")
>                                                         = nil
>     libcrypto.so.1.0.0->getenv("OPENSSL_ALLOW_PROXY_CERTS")
>                                                         = nil
>     libcurl.so.4->getenv("no_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("NO_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("http_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("all_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("ALL_PROXY")
>                                                         = nil
>     libcrypto.so.1.0.0->getenv("OPENSSL_ALLOW_PROXY_CERTS")
>                                                         = nil
>     libcurl.so.4->getenv("no_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("NO_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("http_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("all_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("ALL_PROXY")
>                                                         = nil
>     libcrypto.so.1.0.0->getenv("OPENSSL_ALLOW_PROXY_CERTS")
>                                                         = nil
>     libcurl.so.4->getenv("no_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("NO_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("https_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("HTTPS_PROXY")
>                                                         = nil
>     libcurl.so.4->getenv("all_proxy")
>                                                         = nil
>     libcurl.so.4->getenv("ALL_PROXY")
>                                                         = nil
>     error: failed to download from
> `https://crates.io/api/v1/crates/rustfmt-nightly/1.4.6/download`
>
>     Caused by:
>       [60] SSL peer certificate or SSH remote key was not OK (server
> certificate verification failed. CAfile: none CRLfile: none)
>     +++ exited (status 101) +++
>
> I investigated this `OPENSSL_ALLOW_PROXY_CERTS` variable and I
> concluded that I am not using any such cert--I believe in this case
> libcurl checks an environment variable but would not act on the
> result?  Anyway, I don't use a proxy.  (I just confirmed crates.io is
> not on the blacklist at work.)
>
> Well, I'm not sure what to check next.  I can tell you that the values
> of SSL_CERT_FILE and SSL_CERT_DIR seem to be correct (even though the
> ltrace output truncates them).
>
> Cheers, thanks,
> --sebboh
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 03 Sep 2019 19:04:59 -0700
> From: "Jonathan Lane" <address@hidden>
> To: Ludovic Courtès <address@hidden>
> Cc: <address@hidden>
> Subject: Re: adding environment variables to /etc/config.scm
> Message-ID: <BWQULMK8V3TT.3N6O7DFZ4U3QG@suika>
> Content-Type: text/plain; charset=UTF-8
>
> On Tue Sep 3, 2019 at 11:27 AM Ludovic Courtès wrote:
>> Hello Jonathan,
>
>> Indeed, on Guix System one is not supposed to modify config files in
>> place.
>>
>> Instead, you declare every aspect of your system config in your
>> ‘operating-system’ declaration, and then run ‘reconfigure’ so that it’s
>> in effect.
>>
>> To add environment variables to /etc/environment, you would “extend”
>> ‘session-environment-service-type’, like so:
>>
>>   (simple-service 'cogl-variable session-environment-service-type
>>                   '(("COGL_ATLAS_DEFAULT_BLIT_MODE" . "framebuffer")))
>>
>> The expression above provides a service that you can add to the list in
>> the ‘services’ field of your ‘operating-system’ declaration.
>>
>> HTH!
>>
>> Ludo’.
>
> This worked perfectly, thanks!
>
> Jonathan
>
> --posted from Guix System, now with working Xorg
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 04 Sep 2019 05:30:29 +0300
> From: Mikhail Kryshen <address@hidden>
> To: Tirifto <address@hidden>, address@hidden
> Subject: Re: Report on environment variable issues
> Message-ID: <87r24wpzcq.fsf@home.localdomain>
> Content-Type: text/plain; charset="utf-8"
>
> Tirifto <address@hidden> writes:
>
>> After some investigation, it turned out that GNOME Shell falls back on
>> a certain default value when the variable is empty, which already
>> contains paths that GNOME Shell needs to function properly. So when the
>> user extends the existing value of ‘$XDG_DATA_DIRS’ with another path,
>> the variable is no longer empty, so GNOME Shell never gets to fall back
>> to the paths it actually needs, and crashes instead.
>
> GNOME does this in accordance with XDG Base Directory Specification, see
> https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
>
>   "If $XDG_DATA_DIRS is either not set or empty, a value equal to
>   /usr/local/share/:/usr/share/ should be used."