{"record":{"id":"2bb6c67f162cad1e","repo":"jax-ml/jax","slug":"reshape-not-supported-yet-aval-in-aval-out","errorCode":null,"errorMessage":"reshape not supported yet: {aval_in}, {aval_out}","messagePattern":"reshape not supported yet: (.+?), (.+?)","errorType":"exception","errorClass":"NotImplementedError","httpStatus":null,"severity":"error","filePath":"jax/_src/pallas/fuser/block_spec.py","lineNumber":2467,"sourceCode":"          'reshape with non-matching block size on lanes not supported yet:'\n          f' {block_shape}'\n      )\n    new_block_shape = (*block_shape[:-2], total_block_size)\n\n    def new_block_index_transform(*idxs):\n      *idx, second_to_last, last = block_transform.block_index_transform(*idxs)\n      # last should always be 0\n      if not isinstance(last, int) and last != 0:\n        raise NotImplementedError(\n            'Must select entire block on last dimension for reshape'\n        )\n      return *idx, second_to_last\n\n    return [block_transform.replace(\n                block_shape=new_block_shape,\n                block_index_transform=new_block_index_transform,)]\n\n  raise NotImplementedError(f'reshape not supported yet: {aval_in}, {aval_out}')\n\n\n@register_eval_rule(lax.reshape_p)\ndef _reshape_eval_rule(\n    eval_ctx: KernelEvalContext, x, *, dimensions, new_sizes, sharding\n):\n  del sharding, dimensions, new_sizes\n  out_shape_nones = tuple(\n      _block_size(s) for s in eval_ctx.out_block_specs[0].block_shape\n  )\n  out_shape = tuple(s for s in out_shape_nones if s is not None)\n  # Because we have restricted the pull block spec rule, we can just apply a\n  # basic reshape here.\n  x = x.reshape(out_shape)\n  return x\n\n\n@register_pull_block_spec_rule(lax.reduce_sum_p)","sourceCodeStart":2449,"sourceCodeEnd":2485,"githubUrl":"https://github.com/jax-ml/jax/blob/1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb/jax/_src/pallas/fuser/block_spec.py#L2449-L2485","documentation":"Error \"reshape not supported yet: {aval_in}, {aval_out}\" thrown in jax-ml/jax.","triggerScenarios":"Thrown at jax/_src/pallas/fuser/block_spec.py:2467 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb","analyzedAt":"2026-08-27T09:53:25.647Z","schemaVersion":2},"datasetVersion":"2026-08-27T13:17:12.746Z"}