fix --arch flag to fall back to emulation when native image unavailab… (#3108)

* fix --arch flag to fall back to emulation when native image unavailable, always infer hardware requirement for arch

* better handling of arch filter

* dont cancel in-progress commit workflows and abstract common setup

* cli improvements

fix group handling

* fix cli publish

* alpha.19

---------

Co-authored-by: Aiden McClelland <me@drbonez.dev>

core/src/s9pk/v2/pack.rs

@@ -7,6 +7,7 @@ use clap::Parser;
 use futures::future::{BoxFuture, ready};
 use futures::{FutureExt, TryStreamExt};
 use imbl_value::InternedString;
+use itertools::Itertools;
 use serde::{Deserialize, Serialize};
 use tokio::process::Command;
 use tokio::sync::OnceCell;
@@ -686,7 +687,7 @@ pub async fn pack(ctx: CliContext, params: PackParams) -> Result<(), Error> {
     let manifest = s9pk.as_manifest_mut();
     manifest.git_hash = Some(GitHash::from_path(params.path()).await?);
     if !params.arch.is_empty() {
-        let arches = match manifest.hardware_requirements.arch.take() {
+        let arches: BTreeSet<InternedString> = match manifest.hardware_requirements.arch.take() {
             Some(a) => params
                 .arch
                 .iter()
@@ -695,10 +696,41 @@ pub async fn pack(ctx: CliContext, params: PackParams) -> Result<(), Error> {
                 .collect(),
             None => params.arch.iter().cloned().collect(),
         };
-        manifest
-            .images
-            .values_mut()
-            .for_each(|c| c.arch = c.arch.intersection(&arches).cloned().collect());
+        if arches.is_empty() {
+            return Err(Error::new(
+                eyre!(
+                    "none of the requested architectures ({:?}) are supported by this package",
+                    params.arch
+                ),
+                ErrorKind::InvalidRequest,
+            ));
+        }
+        manifest.images.iter_mut().for_each(|(id, c)| {
+            let filtered = c
+                .arch
+                .intersection(&arches)
+                .cloned()
+                .collect::<BTreeSet<_>>();
+            if filtered.is_empty() {
+                if let Some(arch) = &c.emulate_missing_as {
+                    tracing::warn!(
+                        "ImageId {} is not available for {}, emulating as {}",
+                        id,
+                        arches.iter().join("/"),
+                        arch
+                    );
+                    c.arch = [arch.clone()].into_iter().collect();
+                } else {
+                    tracing::error!(
+                        "ImageId {} is not available for {}",
+                        id,
+                        arches.iter().join("/"),
+                    );
+                }
+            } else {
+                c.arch = filtered;
+            }
+        });
         manifest.hardware_requirements.arch = Some(arches);
     }