fix: avoid modifying source during resolver.Copy

[jedevc]

Fixes #2229

It looks like this case could only happen with multiple sources? But regardless, we definitely shouldn't be modifying a source input, we should instead make a clone.

[dunglas]

I tried it in FrankenPHP's CI and it looks like it triggers another bug:

[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x11e7f95]

goroutine 1985 [running]:
go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace.(*clientTracer).end(0xc005c1da40, {0x23169ef, 0xc}, {0x0?, 0x0?}, {0xc006e63200?, 0x26a2980?, 0x4})
	go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace@v0.45.0/clienttrace.go:231 +0x795
go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace.(*clientTracer).gotConn(0x2699d58?, {{0x26a2980?, 0xc0057e7500?}, 0x0?, 0x50?, 0x3?})
	go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace@v0.45.0/clienttrace.go:288 +0x64d
net/http.http2traceGotConn(0xc00626e1a0?, 0xc006a74c00, 0x1)
	net/http/h2_bundle.go:10239 +0x1dd
net/http.(*http2Transport).RoundTripOpt(0xc000350510, 0xc002930000, {0x40?})
	net/http/h2_bundle.go:7648 +0x19c
net/http.(*http2Transport).RoundTrip(...)
	net/http/h2_bundle.go:7598
net/http.http2noDialH2RoundTripper.RoundTrip({0x3850580?}, 0xc002930000?)
	net/http/h2_bundle.go:10203 +0x16
net/http.(*Transport).roundTrip(0x3850580, 0xc002930000)
	net/http/transport.go:549 +0x39e
net/http.(*Transport).RoundTrip(0x3850300?, 0x2699d58?)
	net/http/roundtrip.go:17 +0x13
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.(*Transport).RoundTrip(0xc000343880, 0xc002a51c00)
	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp@v0.45.0/transport.go:116 +0x52b
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.(*Transport).RoundTrip(0xc002a26fc0, 0xc002a51b00)
	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp@v0.45.0/transport.go:116 +0x52b
net/http.send(0xc002a51b00, {0x2675de0, 0xc002a26fc0}, {0xc0043fe301?, 0xc001a3a5e0?, 0x0?})
	net/http/client.go:260 +0x606
net/http.(*Client).send(0xc002a60210, 0xc002a51b00, {0x7f9e18ebb888?, 0xc006aa9d30?, 0x0?})
	net/http/client.go:181 +0x98
net/http.(*Client).do(0xc002a60210, 0xc002a51b00)
	net/http/client.go:724 +0x912
net/http.(*Client).Do(...)
	net/http/client.go:590
github.com/containerd/containerd/remotes/docker.(*request).do(0xc001a2c900, {0x2699d58, 0xc001a421b0})
	github.com/containerd/containerd@v1.7.12/remotes/docker/resolver.go:591 +0x4e5
github.com/containerd/containerd/remotes/docker.(*request).doWithRetries(0xc001958fc0?, {0x2699d58, 0xc001a421b0}, {0x0, 0x0, 0x0})
	github.com/containerd/containerd@v1.7.12/remotes/docker/resolver.go:600 +0x45
github.com/containerd/containerd/remotes/docker.dockerPusher.push({0xc0001722d0, {0xc000776619, 0x18}, {0x7f9e18f094c8, 0xc00065e6c0}}, {0x2699d58, 0xc001a42180}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, ...}, ...}, ...)
	github.com/containerd/containerd@v1.7.12/remotes/docker/pusher.go:120 +0xb50
github.com/containerd/containerd/remotes/docker.dockerPusher.Push({0xc0001722d0, {0xc000776619, 0x18}, {0x7f9e18f094c8, 0xc00065e6c0}}, {0x2699d58, 0xc001a42180}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, ...}, ...})
	github.com/containerd/containerd@v1.7.12/remotes/docker/pusher.go:67 +0x10c
github.com/moby/buildkit/util/contentutil.(*pushingIngester).Writer(0xc00047e570, {0x2699d58, 0xc001a42180}, {0xc00041dc70, 0x2, 0x7f9e5fcefa68?})
	github.com/moby/buildkit@v0.13.0-beta1.0.20240126101002-6bd81372ad6f/util/contentutil/pusher.go:76 +0x2e8
github.com/containerd/containerd/content.OpenWriter({0x2699d58, 0xc001a42180}, {0x2676e80, 0xc00047e570}, {0xc00041dc70, 0x2, 0x2})
	github.com/containerd/containerd@v1.7.12/content/helpers.go:115 +0xc3
github.com/containerd/containerd/remotes.Fetch({0x2699d58, 0xc001a42180}, {0x2676e80, 0xc00047e570}, {0x267ba60, 0xc00065e768}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, ...})
	github.com/containerd/containerd@v1.7.12/remotes/handlers.go:117 +0x26e
github.com/moby/buildkit/util/resolver/limited.FetchHandler.FetchHandler.func1({0x2699d90, 0xc000172280}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, 0x60d4b86, {0x0, 0x0, 0x0}, ...})
	github.com/containerd/containerd@v1.7.12/remotes/handlers.go:104 +0x2fa
github.com/moby/buildkit/util/contentutil.CopyChain.New.func5({0x2699d90, 0xc000172280}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, 0x60d4b86, {0x0, 0x0, 0x0}, ...})
	github.com/moby/buildkit@v0.13.0-beta1.0.20240126101002-6bd81372ad6f/util/resolver/retryhandler/retry.go:25 +0xb9
github.com/containerd/containerd/images.HandlerFunc.Handle(0x1000?, {0x2699d90?, 0xc000172280?}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, 0x60d4b86, {0x0, 0x0, ...}, ...})
	github.com/containerd/containerd@v1.7.12/images/handlers.go:59 +0x63
github.com/moby/buildkit/util/contentutil.CopyChain.Handlers.func6({0x2699d90, 0xc000172280}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, 0x60d4b86, {0x0, 0x0, 0x0}, ...})
	github.com/containerd/containerd@v1.7.12/images/handlers.go:69 +0x15e
github.com/containerd/containerd/images.HandlerFunc.Handle(0xc0007e3680?, {0x2699d90?, 0xc000172280?}, {{0xc00190eae0, 0x2b}, {0xc001115ae0, 0x47}, 0x60d4b86, {0x0, 0x0, ...}, ...})
	github.com/containerd/containerd@v1.7.12/images/handlers.go:59 +0x63
github.com/containerd/containerd/images.Dispatch.func1()
	github.com/containerd/containerd@v1.7.12/images/handlers.go:168 +0xd6
golang.org/x/sync/errgroup.(*Group).Go.func1()
	golang.org/x/sync@v0.4.0/errgroup/errgroup.go:75 +0x56
created by golang.org/x/sync/errgroup.(*Group).Go in goroutine 1106
	golang.org/x/sync@v0.4.0/errgroup/errgroup.go:72 +0x96

https://github.com/dunglas/frankenphp/actions/runs/7728429011/job/21072578318

[jedevc]

oh no

That one looks absolutely miserable 😢 I think this is unrelated thankfully, so we should be able to merge this one now, and follow-up.

Why in the world would we be getting a SIGSEGV in OTEL code? 😢 😢 It's also coming from something containerd pusher related: realllllly hope it's not related to containerd/containerd#8379.

[crazy-max]

I tried it in FrankenPHP's CI and it looks like it triggers another bug:

@dunglas Would you mind opening another issue with this stacktrace please? Thanks.

[crazy-max]

Why in the world would we be getting a SIGSEGV in OTEL code? 😢 😢 It's also coming from something containerd pusher related: realllllly hope it's not related to containerd/containerd#8379.

Oh right I see the call to the resolver 😳