# Julia 1.12.3 stopped outputting top-level println strings

**URL:** <https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583>\
**Category:** General Usage\
**Created:** [December 16, 2025, 7:15am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583 "2025-12-16T07:15:44Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![phma](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/phma/32/6576_2.png) [@phma](https://discourse.julialang.org/u/phma)\
**Post date:** [December 16, 2025, 7:15am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583/1 "2025-12-16T07:15:44Z")

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I have a repo on two computers, one of which I just upgraded to Julia 1.12.3. There are some `println` statements not in any function. I start Julia on both computers and load the project with `using`. This is output:

```julia-auto
phma@puma:~/src/MumzelCode$ julia --project -t auto
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.12.3 (2025-12-15)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org release
|__/ |

julia> using MumzelCode

julia>

```

```julia-auto
phma@kodkod:~/crypt/src/MumzelCode$ julia --project -t auto
        Info The latest version of Julia in the `release` channel is 1.12.2+0.x64.linux.gnu. You currently have `1.12.1+0.x64.linux.gnu` installed. Run:

  juliaup update

in your terminal shell to install Julia 1.12.2+0.x64.linux.gnu and update the `release` channel to that version.
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.12.1 (2025-10-17)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org release
|__/ |

julia> using MumzelCode
Info Given MumzelCode was explicitly requested, output will be shown live 
Mumzel Code © 2025 Pierre Abbat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 3 or later.
Tables output by this program are in the public domain.
Precompiling MumzelCode finished.
  1 dependency successfully precompiled in 1 seconds. 9 already precompiled.
  1 dependency had output during precompilation:
┌ MumzelCode
│ [Output was shown above]
└  

julia>

```

Why does 1.12.1, but not 1.12.3, run the `println` statements?

---

<div class="post-metadata">

**Author:** ![giordano](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/giordano/32/2166_2.png) [@giordano](https://discourse.julialang.org/u/giordano)\
**Post date:** [December 16, 2025, 8:25am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583/2 "2025-12-16T08:25:03Z")

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Code is

> <https://github.com/phma/MumzelCode.jl/blob/b4ec5181edbb31957b7d9fa928dda9d8af93f6d7/src/MumzelCode.jl#L26-L29>

Top-level statements are only executed during precompilation, not every time the package is loaded (otherwise you’d be redefining all functions all the time), this behaviour has been the same for a very long time. In the first example you shared, it looks like your package was already precompiled.

---

<div class="post-metadata">

**Author:** ![phma](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/phma/32/6576_2.png) [@phma](https://discourse.julialang.org/u/phma)\
**Post date:** [December 16, 2025, 8:35am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583/3 "2025-12-16T08:35:49Z")

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It stopped outputting this on puma when I upgraded it. It also stopped outputting this when I run `]test`; it used to output this every time I tested.

---

<div class="post-metadata">

**Author:** ![GunnarFarneback](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gunnarfarneback/32/1827_2.png) [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)\
**Post date:** [December 16, 2025, 9:12am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583/4 "2025-12-16T09:12:00Z")

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Possible but unverified explanations, i.e. speculation:

- Some bugfix in 1.12.3 has removed some cases of re-precompilation that weren’t needed.
- Some bug in 1.12.3 makes it not re-precompile despite being necessary.

---

<div class="post-metadata">

**Author:** ![sgaure](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sgaure/32/14779_2.png) [@sgaure](https://discourse.julialang.org/u/sgaure)\
**Post date:** [December 16, 2025, 11:10am UTC](https://discourse.julialang.org/t/julia-1-12-3-stopped-outputting-top-level-println-strings/134583/5 "2025-12-16T11:10:37Z")

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If you want things to run when the package is loaded, put it in the ` __init__ ()` function.

> **[Module initialization and precompilation - Modules · The Julia Language](https://docs.julialang.org/en/v1/manual/modules/#Module-initialization-and-precompilation)**
>
> Modules in Julia help organize code into coherent units. They are delimited syntactically inside module NameOfModule ... end, and have the following features: | Documentation for The Julia Language.