Why nix does not show package downloading progress?

I think nix internally use curl to download package file, but the progress i.e., how much has been done and how much still not finished is not showing
e.g.,

trying https://github.com/Bumblebee-Project/Bumblebee/commit/deceb14cdf2c90ff64ebd1010a674305464587da.patch
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 23514    0 23514    0     0  13839      0 --:--:--  0:00:01 --:--:-- 13831
100  139k  100  139k    0     0  30915      0  0:00:04  0:00:04 --:--:-- 82866
exporting path '/nix/store/2cvd040kzrhpkhsvf4z59xb6q10wlqy1-linux-4.14.65-dev' (96980200 bytes)
                                         

The progress should be shown in the next line, but it disappeared.

my term is xfce-terminal

$> echo $TERM 
xterm-256color

How can this information be shown?

2 Likes

This was changed in nix 2.0 - from: Introduction

It is much less verbose. By default, it displays a single-line progress indicator that shows how many packages are left to be built or downloaded, and (if there are running builds) the most recent line of builder output. If a build fails, it shows the last few lines of builder output. The full build log can be retrieved using nix log.

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Note that the download progress that Nix2 shows is the downloads that Nix itself handles. That means downloads for bootstrapping and Nix files. Most other downloads are handled by curl within the build and thus (from what I remember) do not show up in the progress.

If anyone is interested, I’ve made an PR that will let Nix handle more of the downloads that are currently handled by curl. See Use Nix-builtin fetchurl where possible by bobvanderlinden · Pull Request #41147 · NixOS/nixpkgs · GitHub

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Sorry to necro an old thread, but would it somehow be possible to update the bottom-most line of the curl output while the download is running?
When large applications have to be downloaded rebuilding can sometimes hang for hours on a single line looking as follows without any indication of progress:
image

I have been staring at this terminal for about 12 minutes now and nothing has happened, but I am also not sure if there is enough time left to prepare some food in the meantime.