apk: v2 package format error

[mcandre]

When I use fpm to generate Alpine .apk packages, then Alpine is unable to install them.

Trace:

% fpm -t apk -p bin/install-media/alpine/buttery-0.0.22.x86_64.apk --architecture x86_64 bin/buttery-0.0.22/linux/amd64/buttery=/usr/bin/buttery

% cd bin/install-media/alpine
% file buttery-0.0.22.x86_64.apk
buttery-0.0.22.x86_64.apk: gzip compressed data, last modified: Fri Jan 30 21:25:55 2026, from Unix, original size modulo 2^32 2819584
% gunzip -vl buttery-0.0.22.x86_64.apk
method  crc     date  time    compressed uncompressed  ratio uncompressed_name
defla 7707e9d1 Jan 30 15:25      1661781      2819584  41.0% buttery-0.0.22.x86_64.apk
% head -c 256 buttery-0.0.22.x86_64.apk | xxd
00000000: 1f8b 0800 e321 7d69 0003 dd90 c14e c330  .....!}i.....N.0
00000010: 0c86 7bee 5358 e2de 3a69 e8d0 24ae 4c08  ..{.SX..:i..$.L.
00000020: 0978 0394 36a6 8d58 922a 7106 e3e9 4991  .x..6..X.*q...I.
00000030: 76d9 154d 08be 8be5 df76 f2db cdf3 c3ee  v..M.....v......
00000040: fef1 eea9 ba20 58e8 95fa 8e85 f388 b2c7  ..... X.........
00000050: 4a5c 8b6e 2325 6e54 57a1 109d 1415 e025  J\.n#%nTW......%
00000060: 4d9d c889 752c 567e face f972 7f84 2bd8  M...u,V~...r..+.
00000070: 91a7 a899 0c0c 4778 5d5c bdbc 4d5e 3b82  ......Gx]\..M^;.
00000080: 5b18 3233 c5e3 aa1c 2816 011b 6ca4 ac75  [.23....(...l..u
00000090: 1ce7 927d dcf4 2fbd 5aab 86d2 5804 0d07  ...}../.Z...X...
000000a0: 6b28 0019 cb21 c2bb e519 9cf6 59ef c105  k(...!......Y...
000000b0: b6c1 4372 21f0 6cfd 54e7 b82f 1333 f392  ..Cr!.l.T../.3..
000000c0: b66d 3b95 d63c 3463 70ad 1bb5 3791 dad3  .m;..<4cp...7...
000000d0: e7c9 7eae 5e04 4a85 58ff f6bd fe1b 5f54  ..~.^.J.X....._T
000000e0: af88 1200 0400 001f 8b08 00e3 217d 6900  ............!}i.
000000f0: 03ec bd09 7c53 55da 309e b469 1ba0 7083  ....|SU.0..i..p.

% docker run --rm -it -v "$(pwd):/src" alpine ash

# cd /src
# apk add -v --allow-untrusted buttery-0.0.22.x86_64.apk
ERROR: buttery-0.0.22.x86_64.apk: v2 package format error
# echo "$?"
99

# cat /etc/*release*
3.23.3
NAME="Alpine Linux"
ID=alpine
VERSION_ID=3.23.3
PRETTY_NAME="Alpine Linux v3.23"
HOME_URL="https://alpinelinux.org/"
BUG_REPORT_URL="https://gitlab.alpinelinux.org/alpine/aports/-/issues"

Using fpm 1.17.0, Ruby 4.0.1, asdf 0.18.0, on a macOS Sequoia host.

[mcandre]

Same behavior when building the package from an Alpine environment.

% docker run --rm -it -v "$(pwd):/src" alpine ash
# cd /src
# mkdir -p bin/install-media/alpine
# apk add -U ruby tar
# gem install fpm
# fpm -t apk -p bin/install-media/alpine/buttery-0.0.22.x86_64.apk --architecture x86_64 bin/buttery-0.0.22/linux/amd64/buttery=/usr/bin/buttery
Loading flags from rc file .fpm {level: :warn}
Additional options: -s dir --name buttery --version 0.0.22 --description a video editor with manual motion smoothing --url https://github.com/mcandre/buttery --maintainer Andrew Pennebaker <n4jm4@pm.me> --license BSD-3 {level: :warn}
apk output does not currently sign packages. {level: :warn}
It's recommended that your package be installed with '--allow-untrusted' {level: :warn}
Created package {path: "bin/install-media/alpine/buttery-0.0.22.x86_64.apk"}
# apk add --allow-untrusted bin/install-media/alpine/buttery-0.0.22.x86_64.apk
ERROR: bin/install-media/alpine/buttery-0.0.22.x86_64.apk: v2 package format error

[mcandre]

Working around this, by scripting an official Alpine Linux Docker image to build the .apk for me.

https://github.com/mcandre/rockhopper

[jordansissel]

Ahh, sorry you’re having this error. Thanks for the detailed report! :)

[mcandre]

Duplicate of #2131