[PATCH] .gitignore: ignore rustc long type txt files

[PATCH] .gitignore: ignore rustc long type txt files

[Manos Pitsidianakis]

When rustc prints an error containing a long type that doesn't fit in a
line, it will write the whole thing in a .txt file and print messages
like:

  note: the full type name has been written to
  'path/to/subsystem/module_name.long-type-11621316855315349594.txt

Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
during development, so add a gitignore entry.

Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>
---
 .gitignore | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.gitignore b/.gitignore
index 3044b9590f058f94fb5334d75765444066488b8f..529c02d9bc11d17672019e49e5ebeacc168a6cb2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -188,3 +188,6 @@ sphinx_*/
 
 # bc language scripts (not LLVM bitcode)
 !kernel/time/timeconst.bc
+
+# rustc error message long types
+*.long-type-*.txt

---
base-commit: 8bc67e4db64aa72732c474b44ea8622062c903f0
change-id: 20260521-rust-gitignore-long-types-txt-c1e5d0071913

Best regards,
-- 
Manos Pitsidianakis <manos@pitsidianak.is>

Re: [PATCH] .gitignore: ignore rustc long type txt files

[Miguel Ojeda]

On Thu, May 21, 2026 at 12:29 PM Manos Pitsidianakis
<manos@pitsidianak.is> wrote:
>
> When rustc prints an error containing a long type that doesn't fit in a
> line, it will write the whole thing in a .txt file and print messages
> like:
>
>   note: the full type name has been written to
>   'path/to/subsystem/module_name.long-type-11621316855315349594.txt
>
> Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
> kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
> during development, so add a gitignore entry.
>
> Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

Cc'ing Nathan, Nicolas and Kbuild -- I considered whether deleting
these in e.g. `distclean`. They are only error artifacts, i.e. the
build system doesn't create these intentionally -- they come from the
Rust compiler in a minority of error cases (where type names are
long).

So end users shouldn't see them anyway, so I am not sure what the policy is.

In any case, putting these in `.gitignore` shouldn't hurt, and they
are definitely not intended to be committed, so it makes sense
regardless of the cleaning. Thus I will commit it with these notes
unless someone shouts:

    [ Depending on the compiler version and the kind of error, there are
      two possible spellings -- copying them here for reference:

          = note: the full name for the type has been written to
'...long-type-...txt'
          = note: the full type name has been written to '...long-type-...txt'

        - Miguel ]

    [ Moved the lines closer to the existing rust-analyzer one. - Miguel ]

I also wondered about `--verbose` (which probably we don't want to
enable unconditionally) and `-Zwrite-long-types-to-disk=no` (which
could be possible as a nice middle ground if kernel developers prefer
to avoid the files unconditionally -- I asked upstream out of
curiosity if that or something similar is intended to be stable at
some point).

Thanks!

Cheers,
Miguel

Re: [PATCH] .gitignore: ignore rustc long type txt files

[Nathan Chancellor]

On Thu, May 28, 2026 at 01:53:46PM +0200, Miguel Ojeda wrote:
> On Thu, May 21, 2026 at 12:29 PM Manos Pitsidianakis
> <manos@pitsidianak.is> wrote:
> >
> > When rustc prints an error containing a long type that doesn't fit in a
> > line, it will write the whole thing in a .txt file and print messages
> > like:
> >
> >   note: the full type name has been written to
> >   'path/to/subsystem/module_name.long-type-11621316855315349594.txt
> >
> > Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
> > kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
> > during development, so add a gitignore entry.
> >
> > Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>
> 
> Cc'ing Nathan, Nicolas and Kbuild -- I considered whether deleting
> these in e.g. `distclean`. They are only error artifacts, i.e. the
> build system doesn't create these intentionally -- they come from the
> Rust compiler in a minority of error cases (where type names are
> long).
> 
> So end users shouldn't see them anyway, so I am not sure what the policy is.

I view these more like build artifacts since the messages in them are
really only relevant to a specific build instance, so I would probably
clean them up with 'clean' over 'mrproper' / 'distclean'. But if they are in
.gitignore, I don't think it matters too much though, but it does feel
like they should be cleaned up with at least 'distclean'.

-- 
Cheers,
Nathan

Re: [PATCH] .gitignore: ignore rustc long type txt files

[Miguel Ojeda]

On Thu, May 28, 2026 at 10:36 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> I view these more like build artifacts since the messages in them are
> really only relevant to a specific build instance, so I would probably
> clean them up with 'clean' over 'mrproper' / 'distclean'. But if they are in
> .gitignore, I don't think it matters too much though, but it does feel
> like they should be cleaned up with at least 'distclean'.

Sounds good, thanks Nathan!

Then let's land this one and we can discuss that on top. I have
created a "good first issue" for that:

  https://github.com/Rust-for-Linux/linux/issues/1236

Cheers,
Miguel

Re: [PATCH] .gitignore: ignore rustc long type txt files

[Danilo Krummrich]

On 5/21/26 12:21 PM, Manos Pitsidianakis wrote:
> When rustc prints an error containing a long type that doesn't fit in a
> line, it will write the whole thing in a .txt file and print messages
> like:
> 
>   note: the full type name has been written to
>   'path/to/subsystem/module_name.long-type-11621316855315349594.txt
> 
> Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
> kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
> during development, so add a gitignore entry.
> 
> Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

Yes, please. :)

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH] .gitignore: ignore rustc long type txt files

[Miguel Ojeda]

On Thu, May 21, 2026 at 12:29 PM Manos Pitsidianakis
<manos@pitsidianak.is> wrote:
>
> When rustc prints an error containing a long type that doesn't fit in a
> line, it will write the whole thing in a .txt file and print messages
> like:
>
>   note: the full type name has been written to
>   'path/to/subsystem/module_name.long-type-11621316855315349594.txt
>
> Long types like core::result::Result<core::pin::Pin<Box<_, Kmalloc,
> kernel::error::Error>: pin_init::PinInit<Box<_, Kmalloc>, _> are common
> during development, so add a gitignore entry.
>
> Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

Applied to `rust-next` -- thanks everyone!

    [ Depending on the compiler version and the kind of error, there are
      two possible spellings -- copying them here for reference:

          = note: the full name for the type has been written to
'...long-type-...txt'
          = note: the full type name has been written to '...long-type-...txt'

      In addition, we could clean the files as well in one of our
      cleaning Make targets [1][2].

      Another option would be `--verbose` (but it implies more things
      that we probably don't want) or `-Zwrite-long-types-to-disk=no`
      (unstable so far, but a possible alternative if we prefer to
      avoid the files and simply see the long types in the output
      -- I asked upstream Rust about it [3]).

      Link: https://lore.kernel.org/rust-for-linux/CANiq72=cKXdmxEacuGET8fuz_v5eFGB50vnOnKZZJd6iEeAAFA@mail.gmail.com/
[1]
      Link: https://github.com/Rust-for-Linux/linux/issues/1236 [2]
      Link: https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/.60-Zwrite-long-types-to-disk.3Dno.60/near/598310194
[3]

        - Miguel ]

    [ Moved the lines closer to the existing rust-analyzer one. - Miguel ]

Cheers,
Miguel