generated shell script fails to run inside docker container because of empty line before shebang unix

[jm2dev]

Generated shell script under target/pack/bin looks like:

#!/bin/bash
# bla bla

though it runs on my linux machine, it fails to run inside docker container.
The fix consists on removing the first empty line, but ideally it shouldn't appear on generation.

Desired output:

#!/bin/bash
# bla bla

[woky]

Create very simple systemd service file in /etc/systemd/system/foo.service to start the program by the launch script (start) created by pack:

[Service]
ExecStart=/opt/foo/bin/start

Start the service: systemctl start foo

The service won't start and the following will appear in journal (journalctl -n20):

Nov 05 20:50:26 myhost systemd[291]: foo.service: Failed to execute command: Exec format error
Nov 05 20:50:26 myhost systemd[291]: foo.service: Failed at step EXEC spawning /opt/foo/bin/start: Exec format error

The problem is that the first line of the launch script is empty line. I think systemd is being correct (and perhaps strict) here. The shebang line should be the first line in the file.

Perhaps the fix could be something like this?

diff --git a/src/main/twirl/xerial/sbt/pack/launch.scala.txt b/src/main/twirl/xerial/sbt/pack/launch.scala.txt
index 632d466..1a13ffd 100644
--- a/src/main/twirl/xerial/sbt/pack/launch.scala.txt
+++ b/src/main/twirl/xerial/sbt/pack/launch.scala.txt
@@ -1,5 +1,4 @@
-@(opts:xerial.sbt.pack.LaunchScript.Opts, expandedClasspath:Option[String])
-#!/bin/sh
+@(opts:xerial.sbt.pack.LaunchScript.Opts, expandedClasspath:Option[String])#!/bin/sh
 #/*--------------------------------------------------------------------------
 # *  Copyright 2012 Taro L. Saito
 # *

[gijsbert802]

I just ran into this issue. For now I worked around it by using CMD ["sh", "bin/pack-generated-script.sh"] instead of just CMD["bin/pack-generated-script.sh"] in my Dockerfile.

[xerial]

Try sbt-0.9.2 with a fix in #120

[Paulpeter]

Was struggling with this problem for some time where the script ran fine but failed to execute with service, putting the shebang in the first line solved it