Hello Blair,

Debian's Rust Team is working through the png 0.17 -> 0.18 transition
(tracked as rust-team/debcargo-conf#150). shotman currently pins
"png = 0.17.5" in its Cargo.toml, which blocks it from building against
a future png 0.18 archive. When the librust-png-dev package in the
Debian archive bumps to 0.18, shotman FTBFS until its Cargo.toml is
updated.

The attached quilt patch bumps the dependency to png 0.18.1. No source
changes are required: shotman's png use is encoder-only (Encoder::new,
set_depth, set_color, write_header, write_image_data, finish), and
that surface is API-compatible across 0.17 -> 0.18. The 0.18 breaking
changes (Decoder now requires Seek+BufRead, removed Encoder::set_srgb,
improved compression settings API) don't touch shotman's call sites.

I verified locally on the current main branch (0.4.10 tree equivalent):

  cargo build                         -> clean
  cargo test --no-run                 -> clean
  cargo clippy -- -D warnings         -> clean

The same patch was submitted upstream to
~whynothugo/shotman@lists.sr.ht today. Carrying this locally in Debian
lets the transition proceed without waiting on upstream merge and
release; it can be dropped when a new upstream tag is cut.

Patch follows.

Thanks,
Greg Lamberson
---
Description: Bump png dependency to 0.18.1
 The png 0.18 release series is API-compatible with shotman's encoder
 usage (Encoder::new, set_depth, set_color, write_header,
 write_image_data, finish). No source changes are required.
 .
 This unblocks the Debian png 0.17 -> 0.18 transition for shotman
 while upstream review of the equivalent patch is pending.
Author: Greg Lamberson <greg@lamco.io>
Forwarded: https://lists.sr.ht/~whynothugo/shotman/patches
Last-Update: 2026-04-19
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,7 +30,7 @@ wayland-client = "0.31.11"
 wayland-protocols = { version = "0.32.9", features = ["client", "unstable", "staging"] }
 wayland-protocols-wlr = { version = "0.3.9", features = ["client"] }
 smithay-client-toolkit = { version = "0.19.2" }
-png = "0.17.5"
+png = "0.18.1"
 memmap2 = "0.9.0"
 itertools = "0.11.0"
 thiserror = "1.0.32"

We believe that the bug you reported is fixed in the latest version of
shotman, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1134399@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Blair Noctis <ncts@debian.org> (supplier of updated shotman package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Mon, 17 Aug 2026 04:59:14 +0000
Source: shotman
Architecture: source
Version: 0.5.1-1
Distribution: unstable
Urgency: medium
Maintainer: Blair Noctis <ncts@debian.org>
Changed-By: Blair Noctis <ncts@debian.org>
Closes: 1126314 1134399
Changes:
 shotman (0.5.1-1) unstable; urgency=medium
 .
   * New upstream release, Closes: #1126314, #1134399
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 50b08b02275d680cf01209350a42acf729f90462 30072 shotman_0.5.1.orig.tar.xz
 2adbee0e579be824a99fe2feb37427cc14c18c03 4660 shotman_0.5.1-1.debian.tar.xz
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Files:
 76649620d2319419536d50c6db9b6a91 1790 utils optional shotman_0.5.1-1.dsc
 fca60cb51cd4428b4a7b88c2fb93884f 30072 utils optional shotman_0.5.1.orig.tar.xz
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 6a2b9b412b54c4e588fa213a646549fd 5145 utils optional shotman_0.5.1-1_source.buildinfo
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