Trick requires various free third party utilities in order to function. All the following products are used by Trick and may already be installed as part of your OS distribution. **Install any missing dependencies with your operating system's [package manager](https://en.wikipedia.org/wiki/Package_manager).** For most operating systems, the default version of a dependency will be compatitable with Trick. **We strongly recommend that you use your package manager's default versions if they meet Trick's requirements.** Please check the specific OS instructions below for your operating system for more details.
| [gcc] and g++ | 4.8+ | C/C++ Compiler | Compiles Trick and Trick simulations. | |
| [clang]/[llvm] | <=14 | C/C++ Compiler | Utilized by the interface code generator. | Trick Versions <= 19.3 should use LLVM <= 9 |
| [python] | 2.7+ | Programming Language | Lets the user interact with a simulation. | Trick has been tested up to python 3.9 as of 02/21 |
| [perl] | 5.6+ | Programming Language | Allows executable scripts in the bin directory to run. | |
| [java] | 11+ | Programming Language | Necessary for Trick GUIs. | |
| [swig] | 2.x-3.x | Language Interfacing | Connects the python input processor with Trick's C code. | 3.0+ required for some unit tests in make test target. SWIG 4.x is compatible with Trick, but has some issues https://github.com/nasa/trick/issues/1288 |
| [make] | 3.78+ | Build Automation | Automates the building and cleaning of Trick. | |
| [openmotif] | 2.2.0+ | GUI Toolkit | Covers Trick GUIs not made with Java. | |
| [udunits] | 2.x+ | C Unit Library/Database | Provides support for units of physical quantities. | |
Clang/LLVM can be installed and located manually should your package manager fail to acquire it. You can tell Trick where to find Clang/LLVM with the "--with-llvm" configuration option specified [below](TODO).
Trick runs on GNU/Linux and macOS, though any System V/POSIX compatible UNIX workstation should accept the Trick software with very little source code porting. Below are instructions for installing the prerequisites on popular operating systems here at NASA.
Sometimes environment variables affect the Trick build and can cause it to fail. If you find one that isn't listed here, please create an issue and we'll add it to the list.
```
JAVA_HOME # Trick and Maven will use JAVA_HOME to build the GUIs instead of javac in PATH if it is set.
TRICK_HOME # This variable is optional but may cause a Trick build to fail if it is set to the wrong directory.
CFLAGS, CXXFLAGS, LDFLAGS # If these flags are set they may affect flags passed to your compiler and linker
```
#### If You Think The Install Instructions Do Not Work Or Are Outdated
If the Trick tests are passing, you can see *exactly* how we configure our test machines on Github's test integration platform, Github Actions.
If logged into any github account on github.com, you can access the [Actions](https://github.com/nasa/trick/actions) tab on the Trick repo page. Go to [Trick-CI](https://github.com/nasa/trick/actions?query=workflow%3A%22Trick+CI%22), and click the latest passing run. Here you can access a log of our shell commands to configure each OS with dependencies and also the commands we use to install Trick. In fact, that is exactly where I go when I want to update the install guide! @spfennell
It is possible you may have an old version of Trick installed, and Trick's libraries are on your LDPATH and interfering with your new build. The solution is to uninstall the old version before building the new one. Call `sudo make uninstall` from any Trick top level directory and it will remove the old libraries.
The configuration for these tests can be found in the [trick/.github/workflow/test.yml](https://github.com/nasa/trick/blob/master/.github/workflows/test.yml) file.
Trick requires the clang/llvm compiler to compile and link the Trick Interface Code Generator. clang/llvm is available through the [Extra Packages for Enterprise Linux](https://fedoraproject.org/wiki/EPEL) repository. Download and install the 'epel-release' package.
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository. In order to access gtest-devel in the epel repository on RHEL 8 you need to enable the dnf repo CodeReady Linux Builder. In Rocky Linux and Alma Linux you can instead enable the Power Tools Repo. On Oracle Linux 8 you must enable OL8 CodeReady Builder.
Trick requires the clang/llvm compiler to compile and link the Trick Interface Code Generator. clang/llvm is available through the [Extra Packages for Enterprise Linux](https://fedoraproject.org/wiki/EPEL) repository. Download and install the 'epel-release' package.
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository
All packages required for Trick may be installed through apt-get. If your package manager cannot find these packages, try searching for alternatives, or your Ubuntu version may be too old.
#### These instructions are for Intel-based macs. For the latest Apple silicon (M1) instructions see this issue: https://github.com/nasa/trick/issues/1283
3. Install Homebrew, macOS's unofficial package manager. They typically have a single line that can be executed in your terminal to install brew at their homepage at https://brew.sh/
4. Install the following dependencies using brew (note, we do not currently support installing llvm through brew. Trick WILL NOT work with brew's llvm. See step 5).
IMPORTANT: Make sure to follow the instructions for adding java to your path provided by brew. If you missed them, you can see them again by using `brew info java`.
IMPORTANT: Your mac might complain during configuration or build that llvm is downloaded from the internet and can not be trusted. You may need to find a safe solution for this on your own. DO THIS AT YOUR OWN RISK: What worked for us was enabling Settings->Security & Privacy->Privacy->Developer Tools->Terminal.
IMPORTANT: when doing the configure step in the install trick section, you need to point trick to llvm. It is also possible that the current iteration of our configure script will not be able to find the udunits package, so you may need to point trick to udunits as well (I believe this is only an issue on M1 macs).
The following commands will clone the Trick repository into a folder named *trick* in your home directory. You can install multiple copies of Trick in different locations to isolate your simulation environments from one another.
```bash
cd ${HOME}
git clone https://github.com/nasa/trick
```
## 2.) Configure Trick
Navigate to the *trick* directory you just created and run the *configure* script.
The *configure* script will generate makefiles and locate project dependencies automatically. It may be necessary to specify dependency paths manually. Run the following command to see the possible options *configure* will accept. If you are having trouble with this step, make sure there were not details in the OS section of this document that you missed.
Now that Trick has been configured and a makefile has been generated, we can run *make* to compile Trick. To build Trick in 32-bit mode, first set the `TRICK_FORCE_32BIT` environment variable to `1`.
```bash
make
```
## 4.) Optionally Update Your Environment
Gone are the days when you needed to set several environment variables to use Trick. Trick can now be used completely environmentlessly*. You no longer need to set `TRICK_HOME` and friends.
Trick still makes use of shell variables, but their existence is only required during simulation compilation and execution. If they are not set, Trick will infer them without polluting your environment. Furthermore, they will be available to any processes that are spawned as part of compilation or execution, so even your own tools may no longer need these variables to be manually set.
Similarly, Trick does not require its executables to be on your `PATH`, but you may find it convenient to add them if you prefer to not specify the full path to `trick-CP` every time you build a sim. They are located in `bin` under Trick's root directory. However, if you frequently work with multiple versions of Trick, it is often easier to use a full path than to keep changing an environment variable.
Finally, although setting `TRICK_CFLAGS` and `TRICK_CXXFLAGS` is not necessary, it can be useful to do so if you want a set of flags (`-g` or `-Wall`, for instance) to be applied to all simulation builds.
*The exception to this is if you're building in 32-bit mode, in which case the `TRICK_FORCE_32BIT` environment variable must be set to `1` before you build Trick or any simulation.
[Continue to Building A Simulation](../building_a_simulation/Building-a-Simulation)
If you intend to build Trick in 32-bit mode, you will need 32-bit versions of the libraries in the above table. If a 32-bit version of udunits is not available through your package manager, you can build it from [source](ftp://ftp.unidata.ucar.edu/pub/udunits/udunits-2.2.25.tar.gz):
Because java is virtual machine code and is portable, you can copy the java applications that have already been built on a different machine into your trick installation on the target machine. If trick is configured in this way, it no longer relies on maven or calls it (in the target environment only). If you know someone trustworthy who has built Trick already, they can provide the built java code to you (you can skip step 1 below).
Trick jars are all-in-one and contain everything they need to run. You will still need maven on the machine where you build the trick java jars.
1. Pre-build your java code on a machine with trick dependencies, including maven and internet access.
```
# On source machine with trick dependencies, internet, and maven
cd prebuiltTrick && ./configure && make java
```
2. Copy the java jars to the environment that you need to build trick on. They are nested in the libexec directory as specified below. The directory should be at the top level of trick, called trick/trick-offline.
