#I need help with 'EROR Errored(Undef)' supposedly caused by wisp/mist with the wrong Erlang version

1 messages · Page 1 of 1 (latest)

jovial shore
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Wisp is throwing this unclear error message. I found a previous post that says this is caused by encode/2 as a result of using the wrong erlang version. I'm not sure how to debug or fix this as there's very little information provided.

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It's worth noting this is being run within a docker container:

FROM ghcr.io/gleam-lang/gleam:v1.4.1-erlang-alpine

# Install build dependencies
RUN apk add --no-cache gcc musl-dev make wget sqlite sqlite-dev

WORKDIR /build

COPY . /build

# Create DB
RUN chmod +x /build/create_db.sh
RUN /build/create_db.sh

# Compile the project
RUN cd /build \
    && gleam export erlang-shipment \
    && mv build/erlang-shipment /app \
    && rm -r /build

# Run the server
WORKDIR /app

ENTRYPOINT ["/app/entrypoint.sh"]
CMD ["run"]
analog pebble
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is there anything else printed?

jovial shore
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Nope

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Well, the rest of wisp's logs are being printed

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from the wisp logs (on fly.io):

2024-09-19T10:17:09Z app[3287154db30038] jnb [info]"decoding save draft"
2024-09-19T10:17:09Z app[3287154db30038] jnb [info]EROR Errored(Undef)
2024-09-19T10:17:09Z app[3287154db30038] jnb [info]INFO 500 POST /publish
true shard
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Is nothing else printed at all?

analog pebble
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the docker image should have a suitable Erlang version but can you check what it is? with erl

true shard
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That container is OTP27

true shard
jovial shore
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Yeah, it seems to be the correct erlang version:

9185e270a2e198:/app# erl
Erlang/OTP 27 [erts-15.0] [source] [64-bit] [smp:1:1] [ds:1:1:10] [async-threads:1] [jit:ns]

Eshell V15.0 (press Ctrl+G to abort, type help(). for help)
1> ^C
BREAK: (a)bort (A)bort with dump (c)ontinue (p)roc info (i)nfo
       (l)oaded (v)ersion (k)ill (D)b-tables (d)istribution
^C9185e270a2e198:/app#
true shard
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Do you use any @external or NIFs in your application?

jovial shore
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I'd actually forgotten that I had

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Strangely this error is not occuring locally

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But in the container it's giving an issue. It could be from the following external function I'm using:

pub type DateTime = String

@external(erlang, "ffi", "format_iso8601")
pub fn now() -> DateTime{}
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where ffi.erl:

% Taken from https://stackoverflow.com/questions/41777852/erlang-return-time-in-utc-format

-module(ffi).
-export([format_iso8601/0]).

format_iso8601() ->
    {{Year, Month, Day}, {Hour, Min, Sec}} =
        calendar:universal_time(),
    iolist_to_binary(
      io_lib:format(
        "~.4.0w-~.2.0w-~.2.0wT~.2.0w:~.2.0w:~.2.0wZ",
        [Year, Month, Day, Hour, Min, Sec] )).
analog pebble
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btw I suggest using another name for your ffi module than ffi since that is likely to conflict

true shard
#

You want to remove the {} from that external definition as you're saying there that it's valid to call that on JavaScript, but there it will fail

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I couldn't say what the issue is with the exception though.

jovial shore
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All good, thanks for the help

analog pebble
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was it fixed?

jovial shore
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Not yet 😦

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It strangely works with the packages I have locally but rebuilding with no cache leads to this issue

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I fear it might be an external package

analog pebble
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did you change the ffi module name?

jovial shore
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Yes and it's working now!

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That was the problem

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Thank you so much

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I wouldn't have figured it out without your help

analog pebble
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I suppose the build order is different somehow and a different module wins in your Docker environment than locally

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that means some package has a module called ffi and that's not nice, is your packages list long? we could file an issue on the package…

jovial shore
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here's my gleam.toml

[dependencies]
gleam_stdlib = ">= 0.34.0 and < 2.0.0"
wisp = ">= 0.16.0 and < 1.0.0"
sqlight = ">= 0.9.0 and < 1.0.0"
cake = ">= 1.1.1 and < 2.0.0"
argv = ">= 1.0.2 and < 2.0.0"
gleam_crypto = ">= 1.3.0 and < 2.0.0"
mist = ">= 1.2.0 and < 2.0.0"
gleam_http = ">= 3.6.0 and < 4.0.0"
gleam_erlang = ">= 0.25.0 and < 1.0.0"
gleam_otp = ">= 0.12.0 and < 1.0.0"
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I'm not sure how to figure out which one is the cause though

true shard
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The order is deterministic