chezmoi on Android can't connect to Internet/DNS

[ErrrorMaxx]

Describe the bug

chezmoi on Android sometimes can't connect to DNS. So it can't download externals

To reproduce

Idk, it just sometimes work and sometimes it doesn't

Expected behavior

No errors, externals are always can be downloaded

Output of command with the --verbose flag

$ chezmoi --verbose diff
chezmoi: Get "https://github.com/macvk/dnsleaktest/raw/HEAD/dnsleaktest.py": dial tcp: lookup github.com on [::1]:53: read udp [::1]:50174->[::1]:53: read: connection refused

$ chezmoi doctor
RESULT    CHECK                       MESSAGE
failed    latest-version              Get "https://api.github.com/repos/twpayne/chezmoi/releases/latest": dial tcp: lookup api.github.com on [::1]:53: read udp [::1]:57535->[::1]:53: read: connection refused

Output of chezmoi doctor

$ chezmoi doctor
RESULT    CHECK                       MESSAGE
ok        version                     v2.47.0, commit 39bd915f446068862cc3064edb6dbeee795785ca, built at 2024-02-25T20:56:37Z, built by goreleaser
failed    latest-version              Get "https://api.github.com/repos/twpayne/chezmoi/releases/latest": dial tcp: lookup api.github.com on [::1]:53: read udp [::1]:54920->[::1]:53: read: connection refused
ok        os-arch                     android/arm64
ok        uname                       Linux localhost 4.19.191+ #1 SMP PREEMPT Wed Nov 29 21:44:22 CST 2023 aarch64 Android
ok        go-version                  go1.22.0 (gc)
ok        executable                  ~/.local/bin/chezmoi
ok        upgrade-method              replace-executable
ok        config-file                 ~/.config/chezmoi/chezmoi.yaml, last modified 2024-02-27T15:51:50Z
warning   source-dir                  ~/.local/share/chezmoi is a git working tree (dirty)
warning   suspicious-entries          ~/.local/share/chezmoi/home/dot_config/rootmoi/chezmoi.yaml.tmpl
warning   working-tree                ~/.local/share/chezmoi is a git working tree (dirty)
warning   dest-dir                    ~ is a git working tree (dirty)
warning   umask                       077
ok        cd-command                  found /data/data/com.termux/files/usr/bin/zsh
ok        cd-args                     /data/data/com.termux/files/usr/bin/zsh
info      diff-command                not set
ok        edit-command                found /data/data/com.termux/files/usr/bin/micro
ok        edit-args                   micro
ok        git-command                 found /data/data/com.termux/files/usr/bin/git, version 2.44.0
warning   merge-command               vimdiff not found in $PATH
ok        shell-command               found /data/data/com.termux/files/usr/bin/zsh
ok        shell-args                  /data/data/com.termux/files/usr/bin/zsh
info      age-command                 age not found in $PATH
ok        gpg-command                 found /data/data/com.termux/files/usr/bin/gpg, version 2.4.4
info      pinentry-command            not set
info      1password-command           op not found in $PATH
info      bitwarden-command           bw not found in $PATH
info      bitwarden-secrets-command   bws not found in $PATH
info      dashlane-command            dcli not found in $PATH
info      doppler-command             doppler not found in $PATH
info      gopass-command              gopass not found in $PATH
info      keepassxc-command           keepassxc-cli not found in $PATH
info      keepassxc-db                not set
info      keeper-command              keeper not found in $PATH
info      lastpass-command            lpass not found in $PATH
info      pass-command                pass not found in $PATH
info      passhole-command            ph not found in $PATH
info      rbw-command                 rbw not found in $PATH
info      vault-command               vault not found in $PATH
info      vlt-command                 vlt not found in $PATH
info      secret-command              not set

[twpayne]

This is something to do with your system. This is not a bug in chezmoi.

[ErrrorMaxx]

After switching to Termux's chezmoi I found out that after diffing with Termux build (and when all externals are downloaded), then diffing with official build works again (using cached externals).
So turns out that android build without some Termux patches works only partially

$ /data/data/com.termux/files/home/.local/bin/chezmoi diff
chezmoi: Get "https://github.com/macvk/dnsleaktest/raw/HEAD/dnsleaktest.py": dial tcp: lookup github.com on [::1]:53: read udp [::1]:48172->[::1]:53: read: connection refused

$ /data/data/com.termux/files/usr/bin/chezmoi diff
*diff here*

$ /data/data/com.termux/files/home/.local/bin/chezmoi diff
*diff here*

UPD: I did some research and Termux actually has a patch for golang: termux/termux-packages/packages/golang/fix-hardcoded-etc-resolv-conf.sh which fixes DNS resolving on Android

UPD2: This is actually a bug of golang on Android: golang/go#8877

[twpayne]

Thanks for the further investigation and apologies for the too-hasty fix.

If I understand correctly, there are two ways for chezmoi to work around this bug in Go:

1. Build the Android binaries with cgo. This will require the Android SDK.
2. Add a user-configurable DNS server in chezmoi's config and use that on Android.
3. Use https://github.com/mtibben/androiddnsfix.

Of these, (1) is the cleanest but might not be supported by goreleaser (the tool chezmoi uses to build its release binaries), (2) has poor user experience, and (3) strikes me as too much of a hack.

Does the Termux-built chezmoi binary have this same problem?

[ErrrorMaxx]

Patch in Termux is for golang itself. So any binaries built in Termux are patched:

$ gitcd https://github.com/twpayne/chezmoi repos/chezmoi
Cloning into 'repos/chezmoi'...
remote: Enumerating objects: 76049, done.
remote: Counting objects: 100% (5230/5230), done.
remote: Compressing objects: 100% (583/583), done.
remote: Total 76049 (delta 4748), reused 4696 (delta 4627), pack-reused 70819
Receiving objects: 100% (76049/76049), 70.23 MiB | 4.79 MiB/s, done.
Resolving deltas: 100% (42413/42413), done.

$ go build
...

$ ./chezmoi diff -R
*diff here* (externals downloaded)