mktemp: too few X's in template ‘rustup’

[flier]

Problem

Installation scripts don't work on ubuntu 20

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
mktemp: too few X's in template ‘rustup’
rustup: command failed: mktemp -d -t rustup
info: downloading installer
mkdir: cannot create directory ‘’: No such file or directory
rustup: command failed: mkdir -p

$lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 20.04 LTS
Release:	20.04
Codename:	focal

Steps

$mktemp -d -t rustup
mktemp: too few X's in template ‘rustup’

$type -a mktemp
mktemp is /usr/bin/mktemp
mktemp is /bin/mktemp

Possible Solution(s)

Create the temporary directory based on template rustup-XXX

[flier]

It is very strange that it cannot be reproduced on another ubuntu server instance.

[xinbin1122]

I have the same problem.

[kinnison]

What's odd is that seeing this error implies that mktemp -d failed for you. The 'bad' template has been present in rustup-init.sh since 2016 it seems. It is nominally a bug though so I'm reopening this.

The line in question is https://github.com/rust-lang/rustup/blob/master/rustup-init.sh#L75 and it should be pretty simple to add a -XXXX or similar on the end of the template string.

[icodeface]

got same error when $TMPDIR set to an invalid path, hopefully this can help other people.