Package: libc6 Version: 2.39-6 Severity: normal When testing the example given in the mtrace(3) man page, no data are generated:
$ cat t_mtrace.c #include <mcheck.h> #include <stdio.h> #include <stdlib.h> int main(void) { mtrace(); for (unsigned int j = 0; j < 2; j++) malloc(100); /* Never freed--a memory leak */ calloc(16, 16); /* Never freed--a memory leak */ exit(EXIT_SUCCESS); } $ cc -g t_mtrace.c -o t_mtrace t_mtrace.c: In function ‘main’: t_mtrace.c:11:5: warning: ignoring return value of ‘malloc’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 11 | malloc(100); /* Never freed--a memory leak */ | ^~~~~~~~~~~ t_mtrace.c:13:3: warning: ignoring return value of ‘calloc’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 13 | calloc(16, 16); /* Never freed--a memory leak */ | ^~~~~~~~~~~~~~ $ export MALLOC_TRACE=/tmp/t $ ./t_mtrace $ mtrace ./t_mtrace $MALLOC_TRACE Cannot open mtrace data file at /bin/mtrace line 152, <locs> line 4. $ ls $MALLOC_TRACE ls: cannot access '/tmp/t': No such file or directory -- System Information: Debian Release: trixie/sid APT prefers unstable-debug APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable-debug'), (500, 'proposed-updates-debug'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental') Architecture: amd64 (x86_64) Kernel: Linux 6.7.12-amd64 (SMP w/16 CPU threads; PREEMPT) Kernel taint flags: TAINT_WARN Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages libc6 depends on: ii libgcc-s1 14.2.0-1 Versions of packages libc6 recommends: ii libidn2-0 2.3.7-2 Versions of packages libc6 suggests: ii debconf [debconf-2.0] 1.5.87 ii glibc-doc 2.39-6 ii libc-l10n 2.39-6 pn libnss-nis <none> pn libnss-nisplus <none> ii locales 2.39-6 -- debconf information: glibc/disable-screensaver: glibc/kernel-not-supported: glibc/restart-services: glibc/upgrade: true glibc/kernel-too-old: glibc/restart-failed: * libraries/restart-without-asking: true -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)