Feorlen's Other Blog

I wanted a dedicated server to experiment with Swift development on Linux, so I set it up on an Intel NUC (“Next Unit of Computing”) embedded box similar to a Mac Mini. It’s a DE3815TYKHE kit I got from a Tizen developer event a while back. It comes with an Atom E3815 CPU and 2 GB of RAM. I’m not using the onboard 4 GB of flash storage but installed a 256 GB SSD.

Taking advice I found from other users, I updated the BIOS to something known to work as a headless server (without monitor and keyboard) and installed Ubuntu Server 14.04.3 LTS. I could have used the latest 15.10 version, but since Ubuntu has designated 14.04 as a Long Term Support release it’s safe to use for several more years without concern I will be forced to upgrade.

After getting the box set up, next is where to install the Swift dev tools. All the comments I’ve seen seem to expect you will put it in your own home directory, supported by the fact that the file permissions for the contents of the tar package are set to only allow access by the owner. That’s fine if you are doing this on a VM that only you will be using, but I wanted to allow the option of sharing this with another developer on my server. The only reasonable way to do that is put it in a system location and make it owned by root.

The topic of where to actually install a package on a Unix-type server is a religious discussion on the order of which editor to use, so I’ll just say that I put it in /usr/local. (I changed the versioned package directory name to “swift” for convenience.)

The install directions on the Swift download page are good and easy to follow if you are already comfortable with average command-line system administration tasks. (Don’t forget to add the install path to your user’s PATH as described.) Additionally, I installed clang 3.6 as suggested on the github page for anyone on Ubuntu 14.04 LTS.

The directions don’t talk about the install path much. I discovered I had a problem when I got permission errors trying to compile a trivial “Hello, World” example. root could compile, but not anybody else. The solution was to modify all the file permissions so other users can read and execute the needed files. Since I untarred into my install location as root, root already owned all the files so the owner permissions were fine. I didn’t want to universally change everything when adding group and other permissions (plain text files don’t need to be executable, after all) so I did that by hand.

First give group and other users read permissions. Even text files need this, so it’s safe to do it with one recursive command from the top level of my install directory.

chmod -R og+r *

Now locate all the directories and add execute permissions so regular users can traverse the filesystem.

find . -type d -exec chmod og+x {} \;

Finally, identify the remaining files that should be executable by searching for the original owner permissions in a detailed directory listing of everything.

ls -lR | grep rwx

These are the ones I found that only had “rwx” in positions 2-4 indicating permissions for the file owner:

in swift/usr/bin:

-rwxr--r-- 1 root root 56959 Dec 18 23:36 lldb-3.8.0
-rwxr--r-- 1 root root 86318 Dec 18 23:36 lldb-argdumper
-rwxr--r-- 1 root root 927980 Dec 18 23:36 lldb-mi-3.8.0
-rwxr--r-- 1 root root 63672187 Dec 18 23:36 lldb-server-3.8.0
-rwxr--r-- 1 root root 9177 Dec 18 23:35 repl_swift
-rwxr--r-- 1 root root 73808411 Dec 18 23:32 swift
-rwxr--r-- 1 root root 1754089 Dec 18 23:39 swift-build
-rwxr--r-- 1 root root 7683691 Dec 18 23:36 swift-build-tool
-rwxr--r-- 1 root root 856388 Dec 18 23:31 swift-demangle


in swift/usr/lib/swift/linux:

-rwxr--r-- 1 root root 7287250 Dec 18 23:39 libFoundation.so
-rwxr--r-- 1 root root 5037507 Dec 18 23:33 libswiftCore.so
-rwxr--r-- 1 root root 15373 Dec 18 23:33 libswiftGlibc.so
-rwxr--r-- 1 root root 172853 Dec 18 23:39 libXCTest.so


in swift/usr/lib/swift/pm

-rwxr--r-- 1 root root 284768 Dec 18 23:39 libPackageDescription.so


Add execute permissions to these files individually with chmod og+x.

After all this, I was able to compile from a regular user’s home directory.