How to Fix “exec user process caused: exec format error” in Linux

After finishing an enormous challenge, your workforce and also you determined to make use of containerization for the complete challenge within the staging and manufacturing steps to keep away from any environment-related points and last-minute “it works on my machine” statements. But, whereas making a container, you encountered the “exec user process caused: exec format error” and don’t have any clue how to repair this. Don’t fear, as we’re right here to assist. In this information, we are going to clarify the potential causes for this problem, together with some dependable fixes to unravel the “exec user process caused: exec format error” in your Linux system.

Fix “exec user process caused: exec format error” (2023)

What Causes the “exec user process caused: exec format error”

The most typical explanation for the “exec user process caused: exec format error” is the lacking script header equivalent to #!/bin/bash. This leads the container to maneuver into the ready stage with the explanation CrashLoopBackOff once you attempt to run it. Upon checking the container log recordsdata, one can find the precise identify of the error as standard_init_linux.go:300: exec consumer course of brought on “exec format error.”

In addition to the above-mentioned cause, there might be different the explanation why this error happens whereas working with containers:

1. Using the unsuitable script header equivalent to including an area in between.
2. Using some incompatible character encodings whereas writing the scripts
3. Non-matching CPU structure
4. Missing file permissions

This shouldn’t be an exhaustive checklist of potential causes behind this error, however now we have enlisted the commonest causes. That mentioned, listed below are the 5 best options to repair the difficulty in your Linux PC.

How to Fix the “exec user process caused: exec format error”

When writing any script with an interpreted language, it’s at all times advisable to make use of a script header. It tells the shell to make use of which interpreter. You can consider the script header because the entry level for scripts. Just a few issues to bear in mind whereas using a script header:

• A script header ought to begin with a shebang (#!) character.
• The header shouldn’t comprise any areas or every other particular characters.
• Use the suitable headers for the programming language you’re engaged on, and the header also needs to correspond to the actual script and the distro. For instance, if you’re using python 3.x on a Debian-based distro, use the next script header:

#!/bin/python3

While using Alpine Linux, customers have a tendency to make use of the identical bash script headers which are utilized in different Linux distros. For Alpine Linux, many use the next script header:

#!/bin/ash

2. Wrong Character Encoding for Newlines

The newline character appears trivial and is usually ignored whereas troubleshooting, however it’s identified to be a serious explanation for some errors. The newline character is used to indicate the “End Of Line” (EOL). This is interpreted otherwise by Windows and Linux. Windows makes use of CRLF (Carriage Return Line Feed), which interprets newline as rn . On the opposite hand, Linux makes use of LF (Line Feed), which interprets newlines as n .

Suppose you wrote a file in Windows using the CRLF encoding, which when despatched to staging or manufacturing with Linux as an surroundings causes the exec format error. This downside may be solved using some actually easy steps:

• Open the file in any Linux textual content editor of your alternative.
• Use the find-and-replace performance to first seek for the “rn” and exchange it with “n” in all of the areas.
• Alternatively, you may even set it to the Linux encoding if you find yourself writing the precise code.

3. Architecture Mismatch

The system structure mismatch can be probably the most frequent causes for the “exec consumer course of brought on: exec format error“. The containerization know-how was developed to unravel software program environment-related points however not {hardware} ones.

For instance, this often occurs once you’re engaged on initiatives on a system with ARM structure, like with the brand new Apple M-series chipsets. When you push a code to your manufacturing surroundings, which is using an x86 system, it ends in the “exec user process caused: exec format error”. This is as a result of every bit of code when transformed to the decrease stage of directions is totally different for each ARM and x86. Docker detects the Apple M1 Pro platform as “linux/arm64/v8“. To resolve this downside, use the next docker syntax whereas constructing a picture:

docker buildx construct --platform=linux/amd64 -t <image_name>:<model>-amd64 .

Then update your Docker file’s “FROM” assertion using this syntax:

FROM --platform=linux/amd64 <base_image>:<model>

When you execute the above statements, your image will get modified from arm64 to amd64 structure, fixing the difficulty at hand. Let us know if this answer fixes the issues along with your docker deployments.

4. Wrong Script Encoding

The unsuitable script encoding shouldn’t be a standard problem however can be identified to trigger the “exec user process caused: exec format error,” particularly in Windows Pcs. When you begin writing the script, be certain that the encoding is ready to UTF-8. If you might be using VS Code to put in writing the script, you may change the encoding using the next steps:

1. Open the file you need the change the encoding for in VS Code.

2. Go to the “File” menu within the top-left and hover your cursor over the “Preferences” possibility within the drop-down menu. Here, you might want to choose the “Settings” possibility from the sub-menu. Alternatively, you may straight press “CTRL + , (comma)” on the keyboard to entry the Settings menu. This will open the settings menu in a separate tab.

3. In the search bar, sort “encoding” and press Enter. Here, you will note the “Files: Encoding” setting with a drop-down menu.

4. Here, select UTF-8 from the drop-down menu. This will change the encoding format for all world recordsdata opened or modified using VS Code.

Generally, making use of the UTF-8 encoding technique works for many customers. But should you’re nonetheless dealing with the error, you may attempt altering the encoding to UTF8+BOM using the identical steps as talked about above. Here, BOM stands for Byte Order Mark.

If you might be using vim or every other command line-based textual content editor, it makes use of the system-wide encoding format. Check out this text on how to allow UTF-8 assist in Linux.

5. Incorrect Permissions

File Permissions are sometimes ignored whereas engaged on a challenge. Permissions are of three varieties – learn, write, and executable. The final sort is split into three classes of customers – proprietor, consumer, and group. Generally, should you run an executable file with out the right permissions, it’ll give a “Permission Denied” error. But, whereas containerizing an enormous challenge, even a single file with out executable permissions may cause the “exec user process caused: exec format error”. To verify the permissions for each file within the container, use the next steps:

1. First, navigate to the container using the command:

cd <path_to_container>

2. Then, to verify the file permissions of each file within the listing, use the next command:

ls -la

3. To change permissions for a file to executable permission, use the next syntax:

chmod +x <file_name_1> <file_name_2> <file_name_3>

Solve “exec user process caused: exec format error”

Breaking down larger issues into smaller ones will help in fixing them effectively. Here, now we have shared some potential causes for the “exec user process caused: exec format error” together with their options. Hope the options will provide help to to unravel the error. If you might want to know more about file permissions, take a look at our article on file permissions in Linux. In case you face issues in eliminating the error, do tell us within the feedback beneath.