/etc/rc.local fails to launch script (supercollider) on boot - linux

Question

In Debian running headless on an arm-based single-board computer (C.H.I.P.), I have this in my /etc/rc.local
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
source /usr/local/bin/gpio.sh
gpio_export CSID5
gpio_direction CSID5 out
gpio_output CSID5 1
gpio_export XIO_P1
gpio_direction XIO_P1 in
export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket
export DISPLAY=:0
cd /home/chip/Inhibition
now=$(date +"%m_%d_%Y")
date >> "log_$now.log"
jackd -P99 -dalsa -Phw:1 -p8192 -n3 -s -r44100 &
sleep 30
sclang main.scd >> "log_$now.log"
exit 0
when running the script as root with
/etc/rc.local
everything runs as expected.
However when booting the last command (sclang main.scd >> "log_$now.log") is never run. (sclang is the command line interpreter of supercollider). I did try running some test commands to see whether executions stops when launching jack but these commands are executed as expected - it's just supercollider that fails to start at boot time.
any ideas?
PS I remember setting this up in a similar way in a Raspberry pi running Raspbian - can't confirm it now, but I am almost sure that the code was like that.
EDIT
I tried comparing the shell environments from the command prompt (once booted) and from within rc.local (env1 is the command shell, env2 is the rc.local shell):
diff env1 env2
1,2c1,4
< BASH=/bin/bash
< BASHOPTS=checkwinsize:cmdhist:complete_fullquote:expand_aliases:extquote:force_fignore:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
---
> AP_EINT1=193
> AP_EINT3=35
> BASH=/bin/sh
> BASHOPTS=cmdhist:complete_fullquote:extquote:force_fignore:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
4,5c6,7
< BASH_ARGC=()
< BASH_ARGV=()
---
> BASH_ARGC=([0]="1")
> BASH_ARGV=([0]="start")
7,8c9,10
< BASH_LINENO=()
< BASH_SOURCE=()
---
> BASH_LINENO=([0]="0")
> BASH_SOURCE=([0]="/etc/rc.local")
11c13,25
< COLUMNS=120
---
> CSICK=129
> CSID0=132
> CSID1=133
> CSID2=134
> CSID3=135
> CSID4=136
> CSID5=137
> CSID6=138
> CSID7=139
> CSIHSYNC=130
> CSIPCK=128
> CSIVSYNC=131
> DBUS_SESSION_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket
12a27
> DISPLAY=:0
13a29,30
> GPIO=1017
> GPIO_HASH=([TWI1_SCK]="47" [UART1_TX]="195" [LCD_D22]="118" [LCD_DE]="121" [LCD_D23]="119" [LCD_D20]="116" [LCD_D21]="117" [PWM0]="34" [CSICK]="129" [CSID3]="135" [LCD_D13]="109" [CSID2]="134" [LCD_D12]="108" [CSID1]="133" [LCD_D11]="107" [CSID0]="132" [LCD_D10]="106" [CSID7]="139" [CSID6]="138" [CSID5]="137" [LCD_D15]="111" [CSID4]="136" [LCD_D14]="110" [LCD_D19]="115" [LCD_D18]="114" [LCD_HSYNC]="122" [AP_EINT3]="35" [AP_EINT1]="193" [XIO_P3]="1019" [CSIHSYNC]="130" [LCD_CLK]="120" [XIO_P2]="1018" [XIO_P1]="1017" [TWI2_SCK]="49" [XIO_P0]="1016" [XIO_P7]="1023" [XIO_P6]="1022" [XIO_P5]="1021" [XIO_P4]="1020" [TWI1_SDA]="48" [UART1_RX]="196" [CSIVSYNC]="131" [LCD_D2]="98" [LCD_D3]="99" [LCD_D4]="100" [LCD_D5]="101" [LCD_D6]="102" [LCD_VSYNC]="123" [LCD_D7]="103" [TWI2_SDA]="50" [CSIPCK]="128" )
15,18d31
< HISTFILE=/root/.bash_history
< HISTFILESIZE=500
< HISTSIZE=500
< HOME=/root
21c34,35
< IFS=$' \t\n'
---
> IFS='
> '
23,27c37,58
< LC_ALL=en_US.UTF-8
< LC_CTYPE=UTF-8
< LINES=32
< LOGNAME=root
< LS_COLORS='rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:'
---
> LCD_CLK=120
> LCD_D10=106
> LCD_D11=107
> LCD_D12=108
> LCD_D13=109
> LCD_D14=110
> LCD_D15=111
> LCD_D18=114
> LCD_D19=115
> LCD_D2=98
> LCD_D20=116
> LCD_D21=117
> LCD_D22=118
> LCD_D23=119
> LCD_D3=99
> LCD_D4=100
> LCD_D5=101
> LCD_D6=102
> LCD_D7=103
> LCD_DE=121
> LCD_HSYNC=122
> LCD_VSYNC=123
29,30c60
< MAIL=/var/mail/root
< MAILCHECK=60
---
> OLDPWD=/
36,38c66,67
< PPID=489
< PS1='${debian_chroot:+($debian_chroot)}\u#\h:\w\$ '
< PS2='> '
---
> POSIXLY_CORRECT=y
> PPID=1
40a70
> PWM0=34
42c72
< SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
---
> SHELLOPTS=braceexpand:errexit:hashall:interactive-comments:posix
44,48c74,80
< SUDO_COMMAND=/bin/su
< SUDO_GID=1000
< SUDO_UID=1000
< SUDO_USER=chip
< TERM=xterm-256color
---
> TERM=dumb
> TWI1_SCK=47
> TWI1_SDA=48
> TWI2_SCK=49
> TWI2_SDA=50
> UART1_RX=196
> UART1_TX=195
50,53c82,94
< USER=root
< USERNAME=root
< XDG_SESSION_ID=c1
< _=clear
---
> XIO_BASE=1016
> XIO_BASE_FILE=/sys/class/gpio/gpiochip1016/base
> XIO_LABEL_FILE=/sys/class/gpio/gpiochip1016/label
> XIO_P0=1016
> XIO_P1=1017
> XIO_P2=1018
> XIO_P3=1019
> XIO_P4=1020
> XIO_P5=1021
> XIO_P6=1022
> XIO_P7=1023
> _=
> now=10_27_2016
the only weird thing I notice is that /etc/rc.local has BASH set to /bin/sh instead of /bin/bash - I thought that this could be a problem since I do change some env variables so I moved my script (from the first export and bellow) to a run.sh file (which again does work OK on its own) and added this to my /etc/rc.local:
/bin/bash /home/chip/Inhibition/run.sh
unfortunately the results are the same - jack does run but no sclang after that.