$ strace ./foo 2>&1                
execve("./foo", ["./foo"], [/* 51 vars */]) = 0
brk(0)                                  = 0x124a000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d786000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/tls/x86_64/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat("/usr/lib/tls/x86_64", 0x7fff8f075dd0) = -1 ENOENT (No such file or directory)
open("/usr/lib/tls/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat("/usr/lib/tls", 0x7fff8f075dd0)    = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat("/usr/lib/x86_64", 0x7fff8f075dd0) = -1 ENOENT (No such file or directory)
open("/usr/lib/libm.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat("/usr/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=214008, ...}) = 0
mmap(NULL, 214008, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f071d751000
close(3)                                = 0
open("/lib64/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260T\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1125896, ...}) = 0
mmap(NULL, 3150184, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f071d262000
mprotect(0x7f071d363000, 2093056, PROT_NONE) = 0
mmap(0x7f071d562000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x100000) = 0x7f071d562000
close(3)                                = 0
open("/usr/lib/libdl.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/lib64/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200\16\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=18988, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d750000
mmap(NULL, 2109744, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f071d05e000
mprotect(0x7f071d061000, 2093056, PROT_NONE) = 0
mmap(0x7f071d260000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f071d260000
close(3)                                = 0
open("/usr/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220\36\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2098910, ...}) = 0
mmap(NULL, 3965536, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f071cc95000
mprotect(0x7f071ce54000, 2093056, PROT_NONE) = 0
mmap(0x7f071d053000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1be000) = 0x7f071d053000
mmap(0x7f071d059000, 16992, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f071d059000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d74f000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d74d000
arch_prctl(ARCH_SET_FS, 0x7f071d74d740) = 0
mprotect(0x7f071d053000, 16384, PROT_READ) = 0
mprotect(0x7f071d260000, 4096, PROT_READ) = 0
mprotect(0x7f071d562000, 4096, PROT_READ) = 0
mprotect(0x7f071d787000, 4096, PROT_READ) = 0
munmap(0x7f071d751000, 214008)          = 0
gettimeofday({1408482881, 426888}, NULL) = 0
brk(0)                                  = 0x124a000
brk(0x126b000)                          = 0x126b000
open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=3519, ...}) = 0
fstat(3, {st_mode=S_IFREG|0644, st_size=3519, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d785000
read(3, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0\4\0\0\0\0"..., 4096) = 3519
lseek(3, -2252, SEEK_CUR)               = 1267
read(3, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\5\0\0\0\5\0\0\0\0"..., 4096) = 2252
close(3)                                = 0
munmap(0x7f071d785000, 4096)            = 0
mmap(NULL, 528384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d6cc000
mmap(NULL, 528384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f071d64b000
rt_sigaction(SIGBUS, {0x52ea90, ~[RTMIN RT_1], SA_RESTORER, 0x7f071cccbe50}, NULL, 8) = 0
rt_sigaction(SIGFPE, {0x52ea90, ~[RTMIN RT_1], SA_RESTORER, 0x7f071cccbe50}, NULL, 8) = 0
rt_sigaction(SIGILL, {0x52ea90, ~[RTMIN RT_1], SA_RESTORER, 0x7f071cccbe50}, NULL, 8) = 0
rt_sigaction(SIGSEGV, {0x52ea90, ~[RTMIN RT_1], SA_RESTORER, 0x7f071cccbe50}, NULL, 8) = 0
brk(0x128f000)                          = 0x128f000
stat("/usr/lib64/chicken/7/readline.scm", 0x7fff8f047510) = -1 ENOENT (No such file or directory)
stat("./readline.scm", 0x7fff8f046760)  = -1 ENOENT (No such file or directory)
write(2, "\nError", 6
Error)                  = 6
write(2, ": ", 2: )                       = 2
write(2, "(require) cannot load extension", 31(require) cannot load extension) = 31
write(2, ": ", 2: )                       = 2
write(2, "readline", 8readline)                 = 8
write(2, "\n", 1
)                       = 1
write(2, "\n\tCall history:\n", 16
        Call history:
)     = 16
write(2, "\n\t", 2
        )                     = 2
write(2, "foo.scm:1: ##sys#require", 24foo.scm:1: ##sys#require) = 24
write(2, "\t  ", 3        )                     = 3
write(2, "\t<--\n", 5   <--
)                  = 5
exit_group(70)                          = ?
+++ exited with 70 +++