Building successfully but not generating gem5.opt or gem5.fast or gem5.debug

[soniab]

Command used for building:
scons build/RISCV/gem5.opt -j12

Linux version:
NAME="SLES"
VERSION="15-SP5"
VERSION_ID="15.5"
PRETTY_NAME="SUSE Linux Enterprise Server 15 SP5"
ID="sles"
ID_LIKE="suse"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:suse:sles:15:sp5"
DOCUMENTATION_URL="https://documentation.suse.com/"

Already tried methods:

1. using git clone and build
2. downloading and unzip the .zip file and build
3. Deleting the build directory and rebuild gem5
4. building gem5.opt / gem5.fast / gem5.debug

Could you please help me with this?

[ivanaamit]

Hi @soniab, when including terminal output in a message, please copy and paste the text rather than attaching a screenshot. Thank you!

I'm the gem5-GPT bot, here to assist with your queries about the gem5 simulator. Please note that while I aim to provide accurate information, my responses could be wrong or may have been slightly edited for clarity. You can access the gem5-GPT on chat.openai.com/g/g-o3y1y4t8J-gem5-gpt if you subscribe to chatGPT.

It seems like you've been trying multiple methods to build gem5, but you're not getting the expected gem5.opt, gem5.fast, or gem5.debug binaries after running the build command. Let's troubleshoot and identify the possible reasons for this issue, followed by solutions.

Steps to Investigate and Resolve:

1. Verify the SCons Version:
   Make sure you have an appropriate version of SCons installed. gem5 requires SCons 3.0.0 or later. Run the following command to check the version:

   scons --version

   If the version is outdated, you can install a newer version using the package manager or pip:

   sudo zypper install scons

   Or with pip:

   pip install --user scons

2. Check for Errors in the Build Process:
   The build command you are running (scons build/RISCV/gem5.opt -j12) is correct for generating the optimized binary (gem5.opt), but if there were errors during the build process, it may not generate the binaries.

   Re-run the build command, but this time, use the --debug=explain option to see more detailed information about what is happening during the build process:

   scons build/RISCV/gem5.opt --debug=explain -j12

   Check if any errors or warnings are being reported.

3. Check the Build Directory:
   The binaries (gem5.opt, gem5.debug, gem5.fast) should be located inside the build/RISCV directory if the build is successful. Run the following command to see if any files are being generated:

   ls build/RISCV/

   If you don't see any of the expected binaries (gem5.opt, gem5.debug, or gem5.fast), this suggests an issue during the build.

4. Ensure the Appropriate Toolchain is Installed:
   Since you're building for the RISCV architecture, make sure you have the appropriate cross-compilation toolchain installed. For SUSE Linux Enterprise Server, you can install the necessary toolchain by running:

   sudo zypper install gcc gcc-c++ make python3
   sudo zypper install gcc-riscv64-linux-gnu

   Verify that the riscv64-linux-gnu-g++ compiler is available and working:

   riscv64-linux-gnu-g++ --version

5. Verify SCons Target Architecture:
   Ensure that you are targeting the correct architecture. You mentioned using RISCV, but double-check that the architecture folder is correct. You can list available architectures using:

   scons -Q

   Ensure that you're specifying the correct target in your build command. If it needs to be corrected, change the target as follows:

   scons build/ARCH/gem5.opt -j12

   Replace ARCH with the appropriate architecture, such as RISCV, X86, or others as per your configuration.

6. Clean Build and Logs:
   Try doing a clean build and capture the log output:

   scons -c
   scons build/RISCV/gem5.opt -j12 > build_log.txt 2>&1

   Afterward, review build_log.txt for any errors or warnings that might have been overlooked.

7. Dependencies and Libraries:
   Make sure that you have installed all necessary dependencies for gem5 on your system. For SUSE Linux, the following packages are generally required:

   sudo zypper install gcc gcc-c++ python3-devel libzstd-devel libboost-devel

   The libboost and libzstd libraries are commonly used in gem5, and missing them can cause builds to fail.

8. Check for Available Memory:
   Since you are using 12 build threads (-j12), it’s important to ensure that your system has enough memory to handle the parallel compilation. If your system runs out of memory, the build might silently fail. Try reducing the number of jobs:

   scons build/RISCV/gem5.opt -j4

Summary of Steps:

1. Check SCons version and upgrade if necessary.
2. Re-run build with --debug=explain to gather more information about the build process.
3. Ensure the correct toolchain for RISCV is installed.
4. Check that the riscv64-linux-gnu-g++ compiler is functioning.
5. Clean the build directory and recompile while capturing logs.
6. Ensure you have enough memory for the build process and dependencies are installed.

Once you have more detailed build logs or outputs from any of the steps, it will be easier to narrow down the root cause if the issue persists.

[abmerop]

Maybe same as #1536 ?