sbt failed to download launcher - linux

Question

When I am trying to run 'sbt' on terminal, it is showing like this:
downloading sbt launcher 1.5.5
cat: /home/knoldus/.cache/sbt/boot/sbt-launch/1.5.5/sbt-launch-1.5.5.jar.sha1: No such file or directory
shasum: standard input: no properly formatted SHA checksum lines found
failed to download launcher jar: https://repo1.maven.org/maven2/org/scala-sbt/sbt-launch/1.5.5/sbt-launch-1.5.5.jar (shasum mismatch)

Answer 1

i had the same error and i just move to the directory and download the file missing manualy
cd ~/.cache/sbt/boot/sbt-launch/1.5.5/
wget https://repo1.maven.org/maven2/org/scala-sbt/sbt-launch/1.5.5/sbt-launch-1.5.5.jar
then i run
sbt package

Answer 2

You need to install curl. It is used in the sbt launcher shell script to download the file sbt-launch-1.5.5.jar.sha1 mentioned in the error message. If curl is missing, that will result in the error you've observed.

Answer 3

SBT package downloaded from the official website includes sbt-launch.jar in <sbt-install-folder>/bin directory. SBT launcher sbt is a shell script that searches for this JAR. If the JAR is not found, it will try to download it from the internet and fail if the machine is behind a proxy.
So, when this happens, first thing is to check the sbt file location and if sbt-launch.jar is present. If the JAR is missing, it can be copied from the official SBT distribution, even if the machine is behind the proxy or offline.

Answer 4

The issue is apparently with command curl --output not being able to open the output file. In my /usr/bin/sbt there is a function
download_url () {
local url="$1"
local jar="$2"
mkdir -p $(dirname "$jar") && {
if command -v curl > /dev/null; then
curl -L "$url" --output "$jar"
elif command -v wget > /dev/null; then
wget -O "$jar" "$url"
fi
} && [[ -f "$jar" ]]
Changing the curl line to:
curl -L "$url" > "$jar"
Fixed the issue for me. I have no idea what the underlying problem with curl is, but it happened both when installed with apt and snap.