Workflow always results in "Nothing to do" even when forcing rules - snakemake

Question

So as the title says I can't bring my workflow to execute anything, except the all rule...
When Executing the all rule it correctly finds all the input files, so the configfile is okay, every path is correct.
when trying to run without additional tags I get
Building DAG of jobs...
Checking status of 0 jobs.
Nothing to be done
Things I tried:
-f rcorrector -> only all rule
filenameR1.fcor_val1.fq -> MissingRuleException (No Typos)
--forceall -> only all rule
Some more fiddling I can't formulate clearly
please Help
from os import path
configfile:"config.yaml"
RNA_DIR = config["RAW_RNA_DIR"]
RESULT_DIR = config["OUTPUT_DIR"]
FILES = glob_wildcards(path.join(RNA_DIR, '{sample}R1.fastq.gz')).sample
############################################################################
rule all:
input:
r1=expand(path.join(RNA_DIR, '{sample}R1.fastq.gz'), sample=FILES),
r2=expand(path.join(RNA_DIR, '{sample}R2.fastq.gz'), sample=FILES)
#############################################################################
rule rcorrector:
input:
r1=path.join(RNA_DIR, '{sample}R1.fastq.gz'),
r2=path.join(RNA_DIR, '{sample}R2.fastq.gz')
output:
o1=path.join(RESULT_DIR, 'trimmed_reads/corrected/{sample}R1.cor.fq'),
o2=path.join(RESULT_DIR, 'trimmed_reads/corrected/{sample}R2.cor.fq')
#group: "cleaning"
threads: 8
params: "-t {threads}"
envmodules:
"bio/Rcorrector/1.0.4-foss-2019a"
script:
"scripts/Rcorrector.py"
############################################################################
rule FilterUncorrectabledPEfastq:
input:
r1=path.join(RESULT_DIR, 'trimmed_reads/corrected/{sample}R1.cor.fq'),
r2=path.join(RESULT_DIR, 'trimmed_reads/corrected/{sample}R2.cor.fq')
output:
o1=path.join(RESULT_DIR, "trimmed_reads/filtered/{sample}R1.fcor.fq"),
o2=path.join(RESULT_DIR, "trimmed_reads/filtered/{sample}R2.fcor.fq")
#group: "cleaning"
envmodules:
"bio/Jellyfish/2.2.6-foss-2017a",
"lang/Python/2.7.13-foss-2017a"
#TODO: load as module
script:
"/scripts/filterUncorrectable.py"
#############################################################################
rule trim_galore:
input:
r1=path.join(RESULT_DIR, "trimmed_reads/filtered/{sample}R1.fcor.fq"),
r2=path.join(RESULT_DIR, "trimmed_reads/filtered/{sample}R2.fcor.fq")
output:
o1=path.join(RESULT_DIR, "trimmed_reads/{sample}.fcor_val1.fq"),
o2=path.join(RESULT_DIR, "trimmed_reads/{sample}.fcor_val2.fq")
threads: 8
#group: "cleaning"
envmodules:
"bio/Trim_Galore/0.6.5-foss-2019a-Python-3.7.4"
params:
"--paired --retain_unpaired --phred33 --length 36 -q 5 --stringency 1 -e 0.1 -j {threads}"
script:
"scripts/trim_galore.py"

Answer 1

In snakemake, you define final output files of the pipeline as target files and define them as inputs in first rule of the pipeline. This rule is traditionally named as all (more recently as targets in snakemake doc).
In your code, rule all specifies input files of the pipeline, which already exists, and therefore snakemake doesn't see anything to do. It just instead needs to specify output files of interest from the pipeline.
rule all:
input:
expand(path.join(RESULT_DIR, "trimmed_reads/{sample}.fcor_val{read}.fq"), sample=FILES, read=[1,2]),
Why your attempted methods didn't work?
-f not working:
As per doc:
--force, -f
Force the execution of the selected target or the first rule regardless of already created output.
Default: False
In your code, this means rule all, which doesn't have output defined, and therefore nothing happened.
filenameR1.fcor_val1.fq
This doesn't match output of any of the rules and therefore the error MissingRuleException.
--forceall
Same reasoning as that for -f flag in your case.
--forceall, -F
Force the execution of the selected (or the first) rule and all rules it is dependent on regardless of already created output.
Default: False