I agree that Phorge should not fall over because of a deprecation warning.

+1

(Implementation notice: in both phorge and arc, this is handled in PhutilErrorHandler::handleError(), and the check is simply $num === E_DEPRECATED), and maybe E_USER_DEPRECATED.

E_USER_DEPRECATED is also available since php 5.3, so no compatibility issues.

There's no equivalent to setup issues in arc though, so this would have to be shown to the user immediately.

This is a good plan. Would this be opt-in, e.g. this Phorge instance would be the main one with this on but other installs wouldn’t see this by default?

I was thinking "out out", but only visible to admins - and then, only as a yellow notice at the top of the page:

Admin can mark "ignored" if they don't want to see them.

And I only want to show one or two traces, with maybe a count of how many total have happened - right now, there's still many cases (could be easily 1000s of warnings per week - there are still some common flows that have deprecated things).

D25386 and D25387 provide the big "do not crash on deprecation warning", and are probably enough to declare "experimental support for php 8.2" on their own.

D25388 and the stuff that will follow is all about exposing the deprecations in a way that isn't destructive, but allows/encourages installs to report them as bugs.

Maybe also something for this topic!
We update php yesterday on our WSL2 (Ubuntu 22.04) clients to 8.1.22 and pulled the latest arcanist from git after the commit
Now we facing this problem on starting arcanist:

ubu22@NB-CN0100021:/mnt/c/Users/ncoker/workspace$ arc version
[2023-08-15 05:30:35] EXCEPTION: (CommandException) Command failed with error #-1!
COMMAND
php -d variables_order=E -r 'echo json_encode($_ENV);'

STDOUT
{"SUDO_GID":"1000","LESSOPEN":"| \/usr\/bin\/lesspipe %s","HTTPS_PROXY":"http:\/\/127.0.0.1:3128","MAIL":"\/var\/mail\/ubu22","no_proxy":"localhost, 127.0.0.*, 10.*, 172.*, 192.168.*,.apac.igus.net","NODE_EXTRA_CA_CERTS":"\/usr\/local\/share\/ca-certificates\/RootCA.crt","USER":"ubu22","XDG_SESSION_TYPE":"tty","SHLVL":"1","MOTD_SHOWN":"pam","HOME":"\/home\/ubu22","OLDPWD":"\/home\/ubu22","NO_PROXY":"localhost, 127.0.0.*, 10.*, 172.*, 192.168.*,.apac.igus.net","HUSHLOGIN":"FALSE","DBUS_SESSION_BUS_ADDRESS":"unix:path=\/run\/user\/1000\/bus","WSL_DISTRO_NAME":"ubu22","https_proxy":"http:\/\/127.0.0.1:3128","SUDO_UID":"1000","LOGNAME":"ubu22","WSL_INTEROP":"\/run\/WSL\/8_interop","http_proxy":"http:\/\/127.0.0.1:3128","_":"\/usr\/local\/arcanist\/bin\/arc","XDG_SESSION_CLASS":"user","TERM":"xterm-256color","XDG_SESSION_ID":"c1","PATH":"\/usr\/local\/arcanist\/bin:\/usr\/local\/nodejs\/bin:\/opt\/apache-maven\/bin:\/opt\/java\/openjdk\/bin:\/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\... (2,667 more byte(s)) ...

STDERR
(empty) at [<arcanist>/src/future/exec/ExecFuture.php:436]
arcanist(head=master, ref.master=df6c315ace5f)

#0 ExecFuture::raiseResultError(array) called at [<arcanist>/src/future/exec/ExecFuture.php:340]
#1 ExecFuture::resolvex() called at [<arcanist>/src/future/exec/execx.php:17]
#2 execx(string, string) called at [<arcanist>/src/utils/PhutilExecutionEnvironment.php:40]
#3 PhutilExecutionEnvironment::repairMissingVariablesOrder() called at [<arcanist>/support/init/init-script.php:120]
#4 __arcanist_init_script__() called at [<arcanist>/support/init/init-script.php:131]
#5 require_once(string) called at [<arcanist>/support/init/init-arcanist.php:3]
#6 require_once(string) called at [<arcanist>/bin/arc:10]

The command output looks like this:
ubu22@NB-CN0100021:/mnt/c/Users/ncoker/workspace$ php -d variables_order=E -r 'echo json_encode($_ENV);'

{"'WSL_INTEROP":"\/run\/WSL\/8_interop'","'WSL_DISTRO_NAME":"ubu22'","'DISPLAY":":0'","'WT_SESSION":"17a1b7e6-af5d-43fc-b3ca-5e52e8fbded7'","'WT_PROFILE_ID":"{bff75edf-0556-5ab2-8fb0-1bf49d0b713c}'","'WSLENV":"WT_SESSION:BASH_ENV\/u:WT_PROFILE_ID'","'PULSE_SERVER":"unix:\/mnt\/wslg\/PulseServer'","'PWD":"\/home\/ubu22'","'TERM":"xterm-256color'","'WSL2_GUI_APPS_ENABLED":"1'","'XDG_RUNTIME_DIR":"\/mnt\/wslg\/runtime-dir'","'WAYLAND_DISPLAY":"wayland-0'","'HOSTTYPE":"x86_64'","SHELL":"\/bin\/bash","SUDO_GID":"1000","no_proxy":"localhost, 127.0.0.*, 10.*, 172.*, 192.168.*,.apac.igus.net","WSL_DISTRO_NAME":"ubu22","JAVA_HOME":"\/opt\/java\/openjdk","NODE_EXTRA_CA_CERTS":"\/usr\/local\/share\/ca-certificates\/RootCA.crt","SUDO_COMMAND":"\/usr\/sbin\/enter-systemd-namespace ","SUDO_USER":"ubu22","PWD":"\/mnt\/c\/Users\/ncoker\/workspace","LOGNAME":"ubu22","XDG_SESSION_TYPE":"tty","ftp_proxy":"http:\/\/127.0.0.1:3128","MOTD_SHOWN":"pam","HOME":"\/home\/ubu22","LANG":"C.UTF-8","WSL_INTEROP":"\/run\/WSL\/8_interop","LS_COLORS":"rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:","https_proxy":"http:\/\/127.0.0.1:3128","LESSCLOSE":"\/usr\/bin\/lesspipe %s %s","XDG_SESSION_CLASS":"user","TERM":"xterm-256color","LESSOPEN":"| \/usr\/bin\/lesspipe %s","USER":"ubu22","NO_PROXY":"localhost, 127.0.0.*, 10.*, 172.*, 192.168.*,.apac.igus.net","FTP_PROXY":"http:\/\/127.0.0.1:3128","DISPLAY":":0","SHLVL":"1","HTTPS_PROXY":"http:\/\/127.0.0.1:3128","HTTP_PROXY":"http:\/\/127.0.0.1:3128","XDG_SESSION_ID":"c1","http_proxy":"http:\/\/127.0.0.1:3128","XDG_RUNTIME_DIR":"\/run\/user\/1000","WSLENV":"WT_SESSION:BASH_ENV\/u:WT_PROFILE_ID","XDG_DATA_DIRS":"\/usr\/local\/share:\/usr\/share:\/var\/lib\/snapd\/desktop","HUSHLOGIN":"FALSE","PATH":"\/usr\/local\/arcanist\/bin:\/usr\/local\/nodejs\/bin:\/opt\/apache-maven\/bin:\/opt\/java\/openjdk\/bin:\/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\/usr\/bin:\/sbin:\/bin:\/usr\/games:\/usr\/local\/games:\/usr\/lib\/wsl\/lib:\/mnt\/c\/ProgramData\/Oracle\/Java\/javapath:\/mnt\/c\/WINDOWS\/system32:\/mnt\/c\/WINDOWS:\/mnt\/c\/WINDOWS\/System32\/Wbem:\/mnt\/c\/WINDOWS\/System32\/WindowsPowerShell\/v1.0\/:\/mnt\/c\/WINDOWS\/System32\/OpenSSH\/:\/mnt\/c\/Program Files (x86)\/AdminStudio\/9.0\/Common\/:\/mnt\/c\/Program Files\/PuTTY\/:\/mnt\/c\/Program Files\/Git\/cmd:\/mnt\/c\/Program Files\/Microsoft VS Code\/bin:\/mnt\/c\/Program Files\/dotnet\/:\/mnt\/c\/Users\/ncoker\/AppData\/Local\/Microsoft\/WindowsApps:\/mnt\/c\/Program Files (x86)\/Nmap:\/snap\/bin","SUDO_UID":"1000","DBUS_SESSION_BUS_ADDRESS":"unix:path=\/run\/user\/1000\/bus","MAIL":"\/var\/mail\/ubu22","OLDPWD":"\/home\/ubu22","_":"\/usr\/bin\/php"}

thank you @ncoker, but:

1. This is not a task to discuss specific errors when trying to run on php 8, and
2. We don't expect arcanist to work on php 8 yet

You can put your error trace in a new Ponder question, and roll back to php 7 until we announce support for php 8.

You can follow T15064 for updates about specific issues.

@ncoker See T15586 instead

Would taking care of the depreciations bump the minimum PHP version required to run Phorge?
looks good to me otherwise

Would taking care of the depreciations bump the minimum PHP version required to run Phorge?

Not in itself, but we do plan to bump the minimum to 7.1 (in T15047).