Linux system errors
Illegal Instruction
Reviewed for reference consistency: August 11, 2026
the CPU reached an opcode it cannot decode or execute
What 132 Means
The 132 error on the Linux system errors indicates illegal instruction — the cpu reached an opcode it cannot decode or execute. This typically occurs due to a binary compiled for a newer instruction set than the host cpu supports (avx, avx-512, armv8 extensions).
Exit code 132 maps to 128 + 4. The killer is SIGILL, raised when the processor meets an opcode outside the set it implements — the memory address itself may be perfectly valid.
How to fix 132
General informational guidance, not professional advice. Commands can affect your system or data — back up first and proceed at your own risk. FixerCode is an independent reference, not affiliated with any vendor mentioned.
Read the binary's target architecture
The file header names the architecture and ABI the executable was built for, the fastest mismatch check against the host.
file ./your_programRead the host CPU's architecture
uname -m reports what the running kernel and CPU actually implement, for a direct comparison with the binary's header.
uname -mCheck transfer integrity
Comparing the checksum with the value from the build machine rules out a damaged download or copy.
md5sum ./your_program
Technical Background
SIGILL is not a memory fault. The address was reachable; the bytes sitting there simply do not form an instruction this processor model implements. That distinction drives the whole diagnosis: segfaults point at pointers, illegal instructions point at the executable's bytes or the CPU beneath them.
The dominant cause in practice is an instruction-set mismatch. Compilers targeting a specific CPU generation happily bake AVX or NEON instructions into ordinary code paths, and the resulting binary runs everywhere except on processors a generation older — where it dies instantly with signal 4.
Damage produces the same exit. A truncated transfer, a failing disk sector under the binary, or a stray write into code pages can all replace valid instructions with undecodable bytes.
Common Causes
- A binary compiled for a newer instruction set than the host CPU supports (AVX, AVX-512, ARMv8 extensions)
- A corrupted or truncated executable whose bytes no longer decode as valid instructions
- Control flow jumping into data or non-executable memory that decodes as garbage
Typical Scenarios
- A binary built on a modern developer workstation copied to an older server or NAS and crashing on startup
- A downloaded executable damaged in transit, failing with SIGILL the moment execution reaches the damaged region
- A just-in-time compiler emitting code for CPU features it failed to detect correctly
What to Know
Two checks separate the common cases: comparing the binary's target architecture against the host CPU, and confirming the file survived transfer intact. A checksum compared against the build machine catches corruption; an architecture mismatch shows up in the file header.
Frequently Asked Questions
Common questions about Linux 132 error
132 (SIGILL) means the instruction itself is unexecutable; 139 (SIGSEGV) means the instruction was fine but the memory it touched was not. A wrong-architecture binary produces 132; a null pointer produces 139.
Compilers can emit instructions for CPU features the build machine had, such as AVX-512. Any host with an older CPU decodes those bytes as illegal, so the same binary works on new hardware and dies on old.
Mostly, yes. Corrupted downloads, wrong-architecture builds, and memory corruption that overwrote code cover nearly all cases. Hardware CPU faults are rare by comparison.
Related Error Codes
Signal 11 (SIGSEGV) — kernel signal for invalid memory reference segmentation fault
Exit Code 139 — process terminated by segmentation fault (Signal 11 / SIGSEGV)
Self-Abort — the process called abort() after detecting a state it cannot recover from
Trace Trap — a breakpoint or trap instruction fired, normally under a debugger's control
Related Errors From Other Categories
Similar error codes documented across different platforms and systems
Git's internal object database is missing or corrupted.
The operating system denied Git's request for more RAM during a heavy operation.
Git detected corruption inside one of its compressed data bundles (packfiles).
An uncompressed file in Git's internal database has an invalid checksum or zero bytes.