html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue https://github.com/pydata/xarray/issues/7096#issuecomment-1264643360,https://api.github.com/repos/pydata/xarray/issues/7096,1264643360,IC_kwDOAMm_X85LYO0g,1006477,2022-10-02T13:23:06Z,2022-10-02T13:23:06Z,NONE,"Hi, we are getting similar failures when building xarray for Arch Linux riscv64. > I'm not sure what that has to do with xarray though? Does this give the same result? > > ``` > import numpy as np > import pandas as pd > num_dates = np.asarray([0., np.nan]) > flat_num_dates = num_dates.ravel() > flat_num_dates_ns_int = (flat_num_dates * (int(1e9) * 60 * 60 * 24)).astype(np.int64) > flat_num_dates_ns_int > array([ 0, 9223372036854775807]) > ``` I got the same result in riscv64. One thing I could guess is that the sign bit of NaN is not kept during conversions. Some more details could be found at: https://sourceware.org/pipermail/libc-alpha/2022-September/142011.html Repeating the same steps result in `array([0, -9223372036854775808])` in x86_64 and `array([0, 0])` in aarch64. > > Please could you answer the question on whether pandas tests pass? I have tried pandas' tests and got many failures like: ``` E AssertionError: Attributes of DataFrame.iloc[:, 4] (column name=""date"") are different E E Attribute ""dtype"" are different E [left]: float64 E [right]: datetime64[ns] ``` or ``` E AssertionError: numpy array are different E E numpy array values are different (50.0 %) E [index]: [0, 1] E [left]: [1036713600000, -9223372036854775808] E [right]: [1036713600000000000, -9223372036854775808] ``` Quite some of the tests are having NaN in the context as well. So you are probably right that pandas or numpy may be where the problem lies.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1389019400