ts=2026-02-26T18:13:18.445641724Z caller=streamed_block_writer.go:178 level=info msg="finalized downsampled block" mint=1770854400000 maxt=1772064000000 ulid=01KJDJBP3BKRF9RXC2Y7GAEQV1 resolution=300000
panic: cannot reduce resolution to custom buckets schema

goroutine 3325 [running]:
github.com/prometheus/prometheus/model/histogram.(*FloatHistogram).CopyToSchema(0x19c96d0eaff?, 0x0?)
	/go/pkg/mod/github.com/prometheus/prometheus@v0.308.0/model/histogram/float_histogram.go:154 +0x2e6
github.com/thanos-io/thanos/pkg/compact/downsample.(*histogramAggregator).add(0xc00146c390, {0x42d34f0?, 0xc00146c390?, 0xc0018dc3c0?})
	/app/pkg/compact/downsample/downsample.go:363 +0x45
github.com/thanos-io/thanos/pkg/compact/downsample.downsampleBatch({0xc000256f08?, 0x6066d20?, 0x60068?}, 0x493e0, {0x42d34f0, 0xc00146c390}, 0xc000fb6e70)
	/app/pkg/compact/downsample/downsample.go:843 +0x7f
github.com/thanos-io/thanos/pkg/compact/downsample.downsampleHistogramBatch({0xc000256f08?, 0x3386e00?, 0x164}, 0x493e0)
	/app/pkg/compact/downsample/downsample.go:455 +0x154
github.com/thanos-io/thanos/pkg/compact/downsample.downsampleRawLoop({0xc0032cc000?, 0xc000fb6ff8?, 0x1ec7033?}, 0x493e0, 0xc00316d200?, 0xc000fb6fd8, 0x3f09f30)
	/app/pkg/compact/downsample/downsample.go:692 +0x1aa
github.com/thanos-io/thanos/pkg/compact/downsample.DownsampleRaw({0xc0032cc000?, 0x164, 0x11aaa}, 0x493e0)
	/app/pkg/compact/downsample/downsample.go:648 +0x165
github.com/thanos-io/thanos/pkg/compact/downsample.Downsample({0x42de890, 0xc0009d8000}, {0x42a55a0, 0xc000930140}, 0xc0012894a0, {0x42eb020, 0xc001457a20}, {0x7ffe17a25284, 0x9}, 0x493e0)
	/app/pkg/compact/downsample/downsample.go:190 +0xaff
main.processDownsampling({0x42de890, 0xc0009d8000}, {0x42a55a0, 0xc000930140}, {0x4309568, 0xc00094b8f0}, 0xc0012894a0, {0x7ffe17a25284, 0x9}, 0x493e0, ...)
	/app/cmd/thanos/downsample.go:385 +0x845
main.downsampleBucket.func3()
	/app/cmd/thanos/downsample.go:265 +0x255
sync.(*WaitGroup).Go.func1()
	/usr/local/go/src/sync/waitgroup.go:239 +0x4a
created by sync.(*WaitGroup).Go in goroutine 83
	/usr/local/go/src/sync/waitgroup.go:237 +0x73