# Segemtation fault on DGX Spark **URL:** \ **Category:** nvc, nvc++ and nvfortran\ **Created:** [January 11, 2026, 7:51pm UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219 "2026-01-11T19:51:52Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![stefan\_bohl](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@stefan\_bohl](https://forums.developer.nvidia.com/u/stefan_bohl)\ **Post date:** [January 11, 2026, 7:51pm UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219/1 "2026-01-11T19:51:52Z")
Hello, when running the nvfortran compiler on the DGX Spark i get this Segmentation fault (core dumped) Can someone help me? user@spark-9452:~/fortran/f/phaser$ nvfortran --version nvfortran 25.11-0 linuxarm64 target on aarch64 Linux -tp gb10 NVIDIA Compilers and Tools Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved. user@spark-9452:~/fortran/f/phaser$ ---
**Author:** ![MatColgrove](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/matcolgrove/32/14047_2.png) [@MatColgrove](https://forums.developer.nvidia.com/u/MatColgrove)\ **Post date:** [January 12, 2026, 3:57pm UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219/2 "2026-01-12T15:57:22Z")
Hi Stefan\_bohl, A seg fault is a very generic error. Can you provide more details and a reproducing example? -Mat ---
**Author:** ![stefan\_bohl](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@stefan\_bohl](https://forums.developer.nvidia.com/u/stefan_bohl)\ **Post date:** [January 12, 2026, 4:01pm UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219/3 "2026-01-12T16:01:20Z")
Hello Mat, what information, debug logs you need? It is an really old f77 program, that i try to re-run example: user@spark-9452:~/fortran/f/phaser$ ./WMAT\_WO\_CONTROL 1 ```auto PERMEABILITY MUR (*) AS A FUNCTION OF FREQUENCY ====> ``` 1 0.000 0.200 0.400 0.600 0.800 1.000 0.12000E+11 ±------------------±------------------±------------------±------------------±------ \* ---------+ 0.12025E+11 | | | | | \* | 0.12050E+11 | | | | | \* | 0.12075E+11 | | | | | \* | 0.12100E+11 | | | | | \* | 0.12125E+11 | | | | | \* | 0.12150E+11 | | | | | \* | 0.12175E+11 | | | | | \* | 0.12200E+11 | | | | | \* | 0.12225E+11 | | | | | \* | 0.12250E+11 ±------------------±------------------±------------------±------------------±------ \* ---------+ 0.12275E+11 | | | | | \* | 0.12300E+11 | | | | | \* | 0.12325E+11 | | | | | \* | 0.12350E+11 | | | | | \* | 0.12375E+11 | | | | | \* | 0.12400E+11 | | | | | \* | 0.12425E+11 | | | | | \* | 0.12450E+11 | | | | | \* | 0.12475E+11 | | | | | \* | 0.12500E+11 ±------------------±------------------±------------------±------------------±------- \* --------+ 0.12525E+11 | | | | | \* | 0.12550E+11 | | | | | \* | 0.12575E+11 | | | | | \* | 0.12600E+11 | | | | | \* | 0.12625E+11 | | | | | \* | 0.12650E+11 | | | | | \* | 0.12675E+11 | | | | | \* | 0.12700E+11 | | | | | \* | 0.12725E+11 | | | | | \* | 0.000 0.200 0.400 0.600 0.800 1.000 1 ```auto PERMEABILITY MUI (*) AS A FUNCTION OF FREQUENCY ====> ``` 1 0.000 0.001 0.002 0.003 0.004 0.005 0.12000E+11 ±----- \* ----------±------------------±------------------±------------------±------------------+ 0.12025E+11 | \* | | | | | 0.12050E+11 | \* | | | | | 0.12075E+11 | \* | | | | | 0.12100E+11 | \* | | | | | 0.12125E+11 | \* | | | | | 0.12150E+11 | \* | | | | | 0.12175E+11 | \* | | | | | 0.12200E+11 | \* | | | | | 0.12225E+11 | \* | | | | | 0.12250E+11 ±----- \* ----------±------------------±------------------±------------------±------------------+ 0.12275E+11 | \* | | | | | 0.12300E+11 | \* | | | | | 0.12325E+11 | \* | | | | | 0.12350E+11 | \* | | | | | 0.12375E+11 | \* | | | | | 0.12400E+11 | \* | | | | | 0.12425E+11 | \* | | | | | 0.12450E+11 | \* | | | | | 0.12475E+11 | \* | | | | | 0.12500E+11 ±----- \* ----------±------------------±------------------±------------------±------------------+ 0.12525E+11 | \* | | | | | 0.12550E+11 | \* | | | | | 0.12575E+11 | \* | | | | | 0.12600E+11 | \* | | | | | 0.12625E+11 | \* | | | | | 0.12650E+11 | \* | | | | | 0.12675E+11 | \* | | | | | 0.12700E+11 | \* | | | | | 0.12725E+11 | \* | | | | | 0.000 0.001 0.002 0.003 0.004 0.005 Segmentation fault (core dumped) Stefan [segm.zip](https://forums.developer.nvidia.com/uploads/short-url/cRy9RVyXJv6lKYA8kADiphN9IYp.zip) (74.2 KB) ---
**Author:** ![MatColgrove](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/matcolgrove/32/14047_2.png) [@MatColgrove](https://forums.developer.nvidia.com/u/MatColgrove)\ **Post date:** [January 12, 2026, 5:02pm UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219/4 "2026-01-12T17:02:05Z")
Thanks, I needed something to reproduce your error. In this case, the segv is coming from your program and appears to be an out-of-bound access. Note the error is not specific to Spark, but occurs on other ARM systems as well as x86. Compiling with the flags “-O0 -g -Mbounds”, the binary will fail with messages pointing you to the arrays that cause the OOB. I was able to get it to run after applying the following changes. I’m not sure if I’m correct with the array sizes I used (like setting NMAX=20 instead of 2, given that’s the value of NMAX at the start of the program), so please verify these changes. I’m also not sure if the results are correct or not. I’m guessing there are other issues with this code that you might want to investigate. Here’s the diff with my changes: ```auto % diff -u WMAT_WO_CONTROL.f WMAT_WO_CONTROL.mod.f --- WMAT_WO_CONTROL.f 2026-01-11 11:34:29.000000000 -0800 +++ WMAT_WO_CONTROL.mod.f 2026-01-12 08:39:21.859574000 -0800 @@ -990,7 +990,7 @@ RETURN END SUBROUTINE CALFUN (N,X,F) - DIMENSION X(1),F(1) + DIMENSION X(2),F(2) COMPLEX X1,PAR1,AMIEF,EPS,EQUA COMMON/CARM/PAR1,PAR2,AMIEF,EPS COMMON/ASTR/D,DELTA,A @@ -1003,7 +1003,7 @@ SUBROUTINE HYBRI(N,X,F,AJINV,DSTEP,DMAX,ACC,MAXFUN,IPRINT,W,IPCP) C DIESE SUBROUTINE BENUTZT DAS POWELL-HYBRID-VERFAHREN FUER C DIE BERECHNUNG DER TRANZENDENTEN GLEICHUNG F(GAMMA). - DIMENSION X(1),F(1),AJINV(N,N),W(1) + DIMENSION X(2),F(2),AJINV(N,N),W(*) LOGICAL FEHLER PARAMETER (NMAX=2) C SETZE VERSCHIEDENE PARAMETER @@ -1383,7 +1383,7 @@ GO TO 38 1300 END SUBROUTINE INVE(MAT,N,FEHLER) - PARAMETER ( NMAX = 2 ) + PARAMETER ( NMAX = 20 ) REAL MAT(1:NMAX,1:NMAX) LOGICAL FEHLER C ..INVERTIERT DIE MATRIX MAT NACH DEM GAUSS- @@ -1418,7 +1418,7 @@ GOTO 999 ENDIF ENDIF - IF ( GEFUND .EQ. .TRUE. ) EXIT + IF ( GEFUND .EQV. .TRUE. ) EXIT ENDDO C ..MAT(Z,S) IST DAS PIVOTELEMENT MAT(Z,S) = 1.D0 / MAT(Z,S) ``` -Mat ---
**Author:** ![stefan\_bohl](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@stefan\_bohl](https://forums.developer.nvidia.com/u/stefan_bohl)\ **Post date:** [January 13, 2026, 9:23am UTC](https://forums.developer.nvidia.com/t/segemtation-fault-on-dgx-spark/357219/5 "2026-01-13T09:23:06Z")
Hello Mat, thanks, i will check.